Error Supplied data is not a JPEG

Yes, most likely there is a problem with exportAs(). Do you see any error message in the javascript console?

Also, remember that exporting large Scheduler grids may hit the browser limits (most browsers limit the memory that can be used for the generated bitmap). You can try exporting SVG to see if this is the problem (SVG doesn't suffer with this problem).

LineCards:1383 Uncaught TypeError: dp.exportAs is not a function
at createPdfAsBlobOnePage (LineCards:1383)
at downloadPDF (LineCards:1374)
at HTMLButtonElement.onclick (LineCards:364)

Here is the javascript error

Wrong send just now, this one is javascript error

Uncaught Error: Supplied data is not a JPEG
at getJpegSizeFromBytes (jspdf.debug.js:4652)
at Object.jsPDFAPI.processJPEG (jspdf.debug.js:4700)
at Object.jsPDFAPI.addImage (jspdf.debug.js:4596)
at createPdfAsBlobOnePage (LineSchedulers:1305)
at downloadPDF (LineSchedulers:1281)
at HTMLButtonElement.onclick (LineSchedulers:335)

Would you be able to create a sample page that reproduces the problem?

It looks like the output of exportAs() call is not correct but I would expect an exception being thrown during exportAs() execution in that case.

May i know Kanban got exportAs function or not?