I can not login to the server

Nextcloud version (eg, 10.0.2):10
Operating system and version (eg, Ubuntu 16.04):centos7
Apache or nginx version (eg, Apache 2.4.25): apache 2.4.6
PHP version (eg, 5.6):7.1.1

When I log in to the server as an administrator, I get the following message:
Where do I check the error log?
Restarting Apache is the same result.

Internal server error
The server encountered an internal error and could not process your request.
If this error occurs more than once, please contact your server administrator and include the technical information below.
You can find more information in the server log.

Technical Information
Remote address:
Request ID: WUZeeT6xVNHM5bEZd-y1kQAAAAA

Did you look there? Without that information we can’t help you.