Roundcube Installer Warning: "Mimetype to file extension mapping: NOT OK"

I got Roundcube up and running on my CyberPanel managed server, but I noticed this warning in Roundcube’s installer in the third and final “test config” step:

Mimetype to file extension mapping: NOT OK

Roundcube itself runs fine, but I would like to know what this means and how to fix it. How do I fix this in CyberPanel with OpenLiteSpeed?

maybe this will help?

Hello everyone, has anyone managed to make this adjustment on the roundcube? I’ve already tried the procedure in the link above, but without success…