Hi,
this is the error that some of our customers report on their PCs (see the image below).
It doens't occur on all the PCs, and it doesn't occur on our development servers, thus it's very difficult for us to understand the cause of the problem.
The customer reported that, on the PCs where the error occurs, uploads of files with a size smaller than 150 KBs are always succesful, but a greater size than that generates the problem. We still have to verify this feedback, but it might be a clue.
Waiting for help!
Best Regards.