Arc will produce an Internal server error due too a field being too large for the server:

Exception
[HTTP/500] Internal Server Error
{"result":null,"error_code":"ERR-CONDUIT-CORE","error_info":"#1406: Data too long for column 'description' at row 1"}

This was produced by:

• making some change
• arc diff
• asks me if I want to create a commit
• fill in commit message with really long message
• arc will then fail when uploading to the server