Olovhan

I just had exactly the same issue. Also removing 0 at the end worked. This must be a general bug. I have the latest version at the moment.

again, go to https://sebastian.expert/fix-wordpress-an-error-occurred-in-the-upload-please-try-again-later/ and do what it says. This will show you reason for the error – then you can fix it.

Please see this link for more details – it helped me https://sebastian.expert/fix-wordpress-an-error-occurred-in-the-upload-please-try-again-later/

Basically what it says is to use Developer tools in Chrome or Firefox to see the response from async_upload.php file after uploading files (when error message appears). It returns error details in JSON format. Having details it will be easier and a lot faster to resolve the problem.

official doc for markdown states that # should be at the begin. and end.
Problem was that markpad accepted ## with no space, but jetpack requires ##[space]something[space]##

##test## does not work but ## test ## works… so it works fine now.