Currently switching from 19.1 to 20.1. Most of the webapps are ok but with one we get a strange problem.
Using in 19.1 there are no problems.
Configure the webapp to work with 20.1 and the webapp starts running (deleting 19.1 webapp, deleting iis directory, configure 20.1).
Sending a file by using post file there is an error 400.0 Bad request. It looks that it has something to do with the size of file (335 kb). Sending a smaller file doesn't have any issues. However in 19.1 this wasn't an issue.
Nothing has been changed to iis settings (not in 19.1 or 20.1).
Reversing everything back and using 19.1 and everything is ok. Therefor it's something with 20.1
Any thoughts?
[solved - a function deep within our own programma returned after the conversion an unexpected value]