I fixed the issue with apache but I have another with another web socket error.
WebSocket connection to 'ws://coinassist.org/socket.io/?EIO=3&transport=websocket&sid=DyMXotjUG3Ls85LEAAAL' failed: Unexpected response code: 400
any ideas why error?
To fix the invalid-files issue see the discussion in this thread https://community.nodebb.org/topic/15075/nodebb-v1-15-0-rc-0-release-candidate-published/7.
Specifically you need to update the multiparty dependency.
You can ignore the second it is just a warning, that plugin will need a update to use the slugify module in the future.