Edge: 404 not found error on '$:/core/ui/EditorToolbar/preview-type':

[rmunn]

Reproduction:

• Go to https://noteself.github.io/edge/
• Click the + icon to create a new note
• Yellow error appears: "Sync error while processing $:/core/ui/EditorToolbar/preview-type: {"status":404,"name":"not_found","message":"missing","reason":"missing"}

Javascript console shows:

$:/core/modules/utils/logger.js:33  syncer-browser: Dispatching 'save' task: $:/StoryList 
$:/core/modules/utils/logger.js:33  syncer-browser: Dispatching 'load' task: $:/core/ui/EditorToolbar/preview-type 
$:/core/modules/utils/logger.js:33  DbStore:NB2: Error getting tiddler $:/core/ui/EditorToolbar/preview-type from DB n {status: 404, name: "not_found", message: "missing", error: true, reason: "missing"}
$:/core/modules/utils/logger.js:33  syncer-browser: Sync error while processing '$:/core/ui/EditorToolbar/preview-type':
{"status":404,"name":"not_found","message":"missing","reason":"missing"} 
$:/core/modules/utils/logger.js:33  syncer-browser: Dispatching 'save' task: $:/StoryList 
$:/core/modules/utils/logger.js:33  syncer-browser: Dispatching 'save' task: Draft of 'New Tiddler 2' 
$:/core/modules/utils/logger.js:33  syncer-browser: Retrieving skinny tiddler list 

There's more in the console, but I snipped most of it out and kept what looked like the most relevant lines.

This happens most of the time, but not every time, and I haven't yet found a pattern to when it happens or doesn't happen.

Reproduced on both Linux and Windows using Chrome. Also reproduced with Firefox on Linux and with Microsoft Edge on Windows, so it's not browser-dependent.