Cannot export annotations: Error: Failed to execute 'toBlob' on 'HTMLCanvasElement'

[usuyama]

Describe the bug Cannot export annotations with the following error:

SecurityError Failed to execute 'toBlob' on 'HTMLCanvasElement': Tainted canvases may not be exported.

To Reproduce

1. Go to the main annotation page for videos
2. Click on 'Export project' button on the main menu
3. See error

Expected behavior Can export annotations (it worked once, but not anymore. Not sure what's the diff)

Screenshots

Desktop

• OS: Windows 10
• Browser Chrome 77, Edge

Additional context

• Using the hosted version https://vott.z22.web.core.windows.net/
• Azure storage blob as data source
• CORS is enabled (it worked once)
• SAS doesn't expire until next year
• Tried different export settings (json/csv/etc.) but didn't help
• Tried after deleting the exported folder (vott-json-export) on the blob but same error
• Tried browser reload

[usuyama]

By trial and error, I just found a workaround!

I needed to uncheck "Include Images" in the export settings. I guess it tries to get images from canvas but fails with the error.