unsupported opcodes / IE

Hello !

I'm using websocket# to transfer files from ones browser to the server. Those files can be several Go big.

I'm having some troubles with Internet Explorer 11 as sometimes randomly it sends unsupported opcodes like 3,5,7,11,15. This happens mainly on huge files.
I didn't encounter the problem with Firefox nor Chrome so far.

Problem is the websocketServer will throw an exception and close the connection. The browser will throw a close event on the socket and not a error making it hard to identify to make a resume.

Would there be a way to ignore / drop those frames ? I have no idea if that would be critical in the overall process.
Have you ever seen those opcodes ?

Thanks !!

Start by reproducing the issue with Internet Explorer 11 while transferring a large file, then inspect the websocket server path that throws on unsupported opcodes. Determine whether those frames can be safely ignored or dropped without corrupting the transfer; the issue provides no named files, tests, or acceptance criteria.