The code used to work in safari before the latest mac os update to safari Version 12.1.2 (14607.3.9). To see the project a link can be found here: https://kjpou1.github.io/WasmWorker/ The link above works in other major browsers. One peculiar note is that if you open the developer tools and then continue it will work. [Log] Calling Runtime: [wasm-worker] wasmworker.Program:Convert (worker.js, line 19) [Log] StreamData length: 256624 (mono.js, line 2261) [Log] Parsing Stream Document... (mono.js, line 2261) [Log] Creating Html Conversion settings. (mono.js, line 2261) [Log] Converting Parsed Document to Htnl. (mono.js, line 2261) [Log] (mono.js, line 2261, x2) [Log] ----------- Converting document!!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x4) [Log] ----------- Converting document after new settings !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x2) [Log] (mono.js, line 2261, x2) [Log] ----------- WmlToHtmlConverter::ConvertToHtml A !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x2) [Log] (mono.js, line 2261, x2) [Log] ----------- RevisionAcceptor::AcceptRevisions !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x2) [Log] (mono.js, line 2261, x2) [Log] ----------- RevisionProcessor::AcceptRevisions !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x2) [Log] RangeError: Maximum call stack size exceeded. (worker.js, line 27) <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_exec_method_full] <?>.wasm-function[interp_runtime_invoke] <?>.wasm-function[mono_jit_runtime_invoke] <?>.wasm-function[do_runtime_invoke] <?>.wasm-function[mono_runtime_try_invoke] <?>.wasm-function[mono_runtime_invoke] <?>.wasm-function[mono_wasm_invoke_method] wasm-stub mono_wasm_invoke_method (anonymous function) — mono.js:11166 ccall — mono.js:652 (anonymous function) — mono.js:660 call_method — mono.js:8661 call_static_method — mono.js:8737 tryRun — worker.js:21 Output should be as follows taken from safari console when run with developer tools open: [Log] Calling Runtime: [wasm-worker] wasmworker.Program:Convert (worker.js, line 19) [Log] StreamData length: 256624 (mono.js, line 2261) [Log] Parsing Stream Document... (mono.js, line 2261) [Log] Creating Html Conversion settings. (mono.js, line 2261) [Log] Converting Parsed Document to Htnl. (mono.js, line 2261) [Log] (mono.js, line 2261, x2) [Log] ----------- Converting document!!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x4) [Log] ----------- Converting document after new settings !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x2) [Log] (mono.js, line 2261, x2) [Log] ----------- WmlToHtmlConverter::ConvertToHtml A !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x2) [Log] (mono.js, line 2261, x2) [Log] ----------- RevisionAcceptor::AcceptRevisions !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x2) [Log] (mono.js, line 2261, x2) [Log] ----------- RevisionProcessor::AcceptRevisions !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x2) [Log] (mono.js, line 2261, x2) [Log] ----------- WmlToHtmlConverter::ConvertToHtml 1.1 !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x4) [Log] ----------- WmlToHtmlConverter::ConvertToHtml 1.2 !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x4) [Log] ----------- WmlToHtmlConverter::ConvertToHtml 1.3 !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x4) [Log] ----------- WmlToHtmlConverter::ConvertToHtml 2 !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x4) [Log] ----------- WmlToHtmlConverter::ConvertToHtml 3 !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x4) [Log] ----------- WmlToHtmlConverter::ConvertToHtml 4 !!!!!!!!! ---------- (mono.js, line 2261) [Log] (mono.js, line 2261, x2) [Log] <html xmlns="http://www.w3.org/1999/xhtml"><head><meta charset="UTF-8" /><title></title><meta name="Generator" content="PowerTools for Open XML" /><style>span { white-space: pre-wrap; } (worker.js, line 22) p.pt-Title { margin-bottom: 26pt; font-family: Microsoft YaHei UI; font-size: 33pt; line-height: 108%; margin-top: 0; margin-left: 0; margin-right: 0; } span.pt-DefaultParagraphFont { color: #FA5A00; font-family: Microsoft YaHei UI; font-size: 33pt; font-style: normal; font-weight: bold; margin: 0; padding: 0; } table.pt-000000 { border-collapse: collapse; border: none; margin-bottom: .001pt; } td.pt-000001 { vertical-align: top; width: 53.85pt; border-top: none; border-right: solid #DADADA 2.3pt; padding-right: 5.4pt; border-bottom: none; border-left: none; padding-left: 5.4pt; padding-top: 0; padding-bottom: 0; } h1.pt-Heading1 { line-height: 90.0%; font-family: Microsoft YaHei UI; font-size: 26pt; margin-top: 0; margin-left: 0; margin-right: 0; margin-bottom: .001pt; } span.pt-DefaultParagraphFont-000002 { color: #FA5A00; font-family: Microsoft YaHei UI; font-size: 26pt; font-style: normal; font-weight: bold; margin: 0; padding: 0; } td.pt-000003 { vertical-align: top; width: 320.45pt; border-top: none; border-right: none; padding-right: 5.4pt; border-bottom: none; border-left: solid #DADADA 2.3pt; padding-left: 5.4pt; padding-top: 0; padding-bottom: 0; } p.pt-Normal { font-family: Microsoft YaHei UI; font-size: 11pt; line-height: 108%; margin-top: 0; margin-left: 0; margin-right: 0; margin-bottom: .001pt; } span.pt-DefaultParagraphFont-000004 { color: #404040; font-family: Microsoft YaHei UI; font-size: 11pt; font-style: normal; font-weight: normal; margin: 0; padding: 0; } td.pt-000005 { vertical-align: top; width: 133.15pt; border-top: none; border-right: none; padding-right: 5.4pt; border-bottom: none; border-left: none; padding-left: 5.4pt; padding-top: 0; padding-bottom: 0; } tr.pt-000006 { height: 0.44in; } td.pt-000007 { vertical-align: top; width: 53.85pt; border-top: none; border-right: none; padding-right: 5.4pt; border-bottom: none; border-left: none; padding-left: 5.4pt; padding-top: 0; padding-bottom: 0; } span.pt-000008 { color: #FA5A00; font-size: 26pt; font-style: normal; font-weight: bold; margin: 0; padding: 0; } td.pt-000009 { vertical-align: top; width: 320.45pt; border-top: none; border-right: none; padding-right: 5.4pt; border-bottom: none; border-left: none; padding-left: 5.4pt; padding-top: 0; padding-bottom: 0; } span.pt-000010 { color: #404040; font-size: 11pt; font-style: normal; font-weight: normal; margin: 0; padding: 0; } </style></head><body><div><p dir="ltr" class="pt-Title"><span lang="zh-CN" class="pt-DefaultParagraphFont">5 日游行程计划</span></p><div align="left"><table dir="ltr" class="pt-000000"><tr><td class="pt-000001"><h1 dir="ltr" class="pt-Heading1"><span lang="zh-CN" class="pt-DefaultParagraphFont-000002">第</span></h1><h1 dir="ltr" class="pt-Heading1"><span lang="zh-CN" class="pt-DefaultParagraphFont-000002">1 天</span></h1></td><td class="pt-000003"><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">目的地</span><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">：[</span><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">您要去哪儿</span><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">？]</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">在哪里吃饭：[早餐吃什么？]</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">安排什么活动：[是否要买演出的票？]</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">待在哪里</span><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">：[沙滩屋还是朋友的沙发？]</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">抵达方式：[飞机、火车还是 GPS 自驾？]</span></p></td><td class="pt-000005"><p dir="ltr" class="pt-Normal" /></td></tr><tr class="pt-000006"><td class="pt-000007"><h1 dir="ltr" class="pt-Heading1"><span xml:space="preserve" class="pt-000008"> </span></h1></td><td class="pt-000009"><p dir="ltr" class="pt-Normal"><span xml:space="preserve" class="pt-000010"> </span></p></td><td class="pt-000005"><p dir="ltr" class="pt-Normal"><span xml:space="preserve" class="pt-000010"> </span></p></td></tr><tr><td class="pt-000001"><h1 dir="ltr" class="pt-Heading1"><span lang="zh-CN" class="pt-DefaultParagraphFont-000002">第</span></h1><h1 dir="ltr" class="pt-Heading1"><span lang="zh-CN" class="pt-DefaultParagraphFont-000002">2 天</span></h1></td><td class="pt-000003"><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">[要替换任何占位符文本（例如此文本），只需选中一行或一段文本并开始键入。为达到最佳效果，请勿在您选中的字符左侧或右侧包含空格。]</span></p></td><td class="pt-000005"><p dir="ltr" class="pt-Normal" /></td></tr><tr class="pt-000006"><td class="pt-000007"><h1 dir="ltr" class="pt-Heading1"><span xml:space="preserve" class="pt-000008"> </span></h1></td><td class="pt-000009"><p dir="ltr" class="pt-Normal"><span xml:space="preserve" class="pt-000010"> </span></p></td><td class="pt-000005"><p dir="ltr" class="pt-Normal"><span xml:space="preserve" class="pt-000010"> </span></p></td></tr><tr><td class="pt-000001"><h1 dir="ltr" class="pt-Heading1"><span lang="zh-CN" class="pt-DefaultParagraphFont-000002">第</span></h1><h1 dir="ltr" class="pt-Heading1"><span lang="zh-CN" class="pt-DefaultParagraphFont-000002">3 天</span></h1></td><td class="pt-000003"><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">[要将任何占位符照片替换为您自己的照片，请删除它，然后在功能区的“插入”选项卡上单击“图片”。]</span></p></td><td class="pt-000005"><p dir="ltr" class="pt-Normal" /></td></tr><tr class="pt-000006"><td class="pt-000007"><h1 dir="ltr" class="pt-Heading1"><span xml:space="preserve" class="pt-000008"> </span></h1></td><td class="pt-000009"><p dir="ltr" class="pt-Normal"><span xml:space="preserve" class="pt-000010"> </span></p></td><td class="pt-000005"><p dir="ltr" class="pt-Normal"><span xml:space="preserve" class="pt-000010"> </span></p></td></tr><tr><td class="pt-000001"><h1 dir="ltr" class="pt-Heading1"><span lang="zh-CN" class="pt-DefaultParagraphFont-000002">第</span></h1><h1 dir="ltr" class="pt-Heading1"><span lang="zh-CN" class="pt-DefaultParagraphFont-000002">4 天</span></h1></td><td class="pt-000003"><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">目的地：</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">在哪里吃饭：</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">安排什么活动：</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">待在哪里</span><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">：</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">抵达方式：</span></p></td><td class="pt-000005"><p dir="ltr" class="pt-Normal" /></td></tr><tr class="pt-000006"><td class="pt-000007"><h1 dir="ltr" class="pt-Heading1"><span xml:space="preserve" class="pt-000008"> </span></h1></td><td class="pt-000009"><p dir="ltr" class="pt-Normal"><span xml:space="preserve" class="pt-000010"> </span></p></td><td class="pt-000005"><p dir="ltr" class="pt-Normal"><span xml:space="preserve" class="pt-000010"> </span></p></td></tr><tr><td class="pt-000001"><h1 dir="ltr" class="pt-Heading1"><span lang="zh-CN" class="pt-DefaultParagraphFont-000002">第</span></h1><h1 dir="ltr" class="pt-Heading1"><span lang="zh-CN" class="pt-DefaultParagraphFont-000002">5 天</span></h1></td><td class="pt-000003"><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">目的地：</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">在哪里吃饭：</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">安排什么活动：</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">待在哪里</span><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">：</span></p><p dir="ltr" class="pt-Normal"><span lang="zh-CN" class="pt-DefaultParagraphFont-000004">抵达方式：</span></p></td><td class="pt-000005"><p dir="ltr" class="pt-Normal" /></td></tr></table></div><p dir="ltr" class="pt-Normal"><span xml:space="preserve" class="pt-000010"> </span></p></div></body></html>
Here is a link that runs the same code but not within a webworker. https://kjpou1.github.io/WasmWorker2/
The second link https://kjpou1.github.io/WasmWorker2/ works correctly. As it just seems to be the one run in the webworker.
<rdar://problem/54513810>
Just an additional comment is that the first link using webworker also works in mobile safari on iphone.
*** This bug has been marked as a duplicate of bug 206436 ***