can not be uploaded, Error message:

Cyberpanel 1.8.8

Using the file manager to upload a file of 2.87mb (WP Plugin)

I get the error message: "can not be uploaded, Error message: "

I’ve cleared browser cache, fixed permissions and restarted Litespeed and PureFTP Server.

What can be done to fix this problem?

First thing you need to do is to upgrade. Otherwise also check CyberPanel main log file and see what it says.

At last I figured this out. We are all behind Cloudflare Free plan, which have 100MB upload limit. After turning of Cloudflare orenge icon, I can upload file of any size.