Internal server error after installing onlyoffice

Hi Guys…

It´s a VPS with
Ubuntu19.10
8 core Xeon E5
30GB ram
Apache2
Mysql(mariadb)

after the last problem with the slow browser upload speed i´ve done a complete clean install.
The nextcloud server was working fine. I have installed nextcloud with this guide:

Then I wanted to install onlyoffice using this guide:

after i finished the installation of olnyoffice i was able to see the “Document server is running” message.

Now i´m facing the problem with this error code:

Internal Server Error
The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
More details can be found in the server log.

The nextcloud log shows lines like this:

{“reqId”:“2AgeCLNRYlSM4iPCSrJ8”,“level”:2,“USERe”:“2020-04-30T08:57:28+02:00”,“remoteAddr”:“108.162.229.173”,“user”:"–",“app”:“core”,“method”:“PROPFIND”,“url”:"/remote.php/dav/uploads/USER/229d85425dd7c71a9ca7e3deea577eb7",“message”:“Login failed: ‘USER’ (Remote IP: ‘ip’)”,“userAgent”:“Mozilla/5.0 (Android) Nextcloud-android/3.11.1”,“version”:“18.0.4.2”}
{“reqId”:“6NVNI1adqq0tItEOFvJk”,“level”:2,“USERe”:“2020-04-30T08:57:55+02:00”,“remoteAddr”:“141.101.69.212”,“user”:"–",“app”:“core”,“method”:“MKCOL”,“url”:"/remote.php/dav/uploads/USER/e88cf75279fa02f0eac8f7ab69240bd4",“message”:“Login failed: ‘USER’ (Remote IP: ‘ip’)”,“userAgent”:“Mozilla/5.0 (Android) Nextcloud-android/3.11.1”,“version”:“18.0.4.2”}
{“reqId”:“yuJmf4Dh12qBzwhau7ah”,“level”:2,“USERe”:“2020-04-30T08:58:22+02:00”,“remoteAddr”:“141.101.69.160”,“user”:"–",“app”:“core”,“method”:“PROPFIND”,“url”:"/remote.php/dav/uploads/USER/e88cf75279fa02f0eac8f7ab69240bd4",“message”:“Login failed: ‘USER’ (Remote IP: ‘ip’)”,“userAgent”:“Mozilla/5.0 (Android) Nextcloud-android/3.11.1”,“version”:“18.0.4.2”}
{“reqId”:“XnlTcHht6LbGO95P5Li8”,“level”:2,“USERe”:“2020-04-30T08:58:48+02:00”,“remoteAddr”:“108.162.229.173”,“user”:"–",“app”:“core”,“method”:“MKCOL”,“url”:"/remote.php/dav/uploads/USER/ac1fe18ffe6d2f0cb2105aec97f0b2c6",“message”:“Login failed: ‘USER’ (Remote IP: ‘ip’)”,“userAgent”:“Mozilla/5.0 (Android) Nextcloud-android/3.11.1”,“version”:“18.0.4.2”}
{“reqId”:“TPSCkfxMBVr3d78mAtYh”,“level”:2,“USERe”:“2020-04-30T09:11:33+02:00”,“remoteAddr”:“141.101.69.106”,“user”:"–",“app”:“core”,“method”:“PROPFIND”,“url”:"/remote.php/dav/uploads/USER/ac1fe18ffe6d2f0cb2105aec97f0b2c6",“message”:“Login failed: ‘USER’ (Remote IP: ‘ip’)”,“userAgent”:“Mozilla/5.0 (Android) Nextcloud-android/3.11.1”,“version”:“18.0.4.2”}
{“reqId”:“KCl2k17HefWV1YtcBt9w”,“level”:2,“USERe”:“2020-04-30T09:12:00+02:00”,“remoteAddr”:“141.101.69.160”,“user”:"–",“app”:“core”,“method”:“MKCOL”,“url”:"/remote.php/dav/uploads/USER/33c4341304a1d4c58d2fdbeedc8cdf14",“message”:“Login failed: ‘USER’ (Remote IP: ‘ip’)”,“userAgent”:“Mozilla/5.0 (Android) Nextcloud-android/3.11.1”,“version”:“18.0.4.2”}
{“reqId”:“3D9JKTH4vrWbAGQe0iFZ”,“level”:2,“USERe”:“2020-04-30T09:12:26+02:00”,“remoteAddr”:“108.162.229.19”,“user”:"–",“app”:“core”,“method”:“PROPFIND”,“url”:"/remote.php/dav/uploads/USER/33c4341304a1d4c58d2fdbeedc8cdf14",“message”:“Login failed: ‘USER’ (Remote IP: ‘ip’)”,“userAgent”:“Mozilla/5.0 (Android) Nextcloud-android/3.11.1”,“version”:“18.0.4.2”}
{“reqId”:“0b96lLzH4TfTs7NzOUMT”,“level”:2,“USERe”:“2020-04-30T09:12:53+02:00”,“remoteAddr”:“108.162.229.19”,“user”:"–",“app”:“core”,“method”:“MKCOL”,“url”:"/remote.php/dav/uploads/USER/ac1fe18ffe6d2f0cb2105aec97f0b2c6",“message”:“Login failed: ‘USER’ (Remote IP: ‘ip’)”,“userAgent”:“Mozilla/5.0 (Android) Nextcloud-android/3.11.1”,“version”:“18.0.4.2”}
{“reqId”:“XCVVcqr55hBygqyggvZZ”,“level”:2,“USERe”:“2020-04-30T09:13:20+02:00”,“remoteAddr”:“141.101.69.68”,“user”:"–",“app”:“core”,“method”:“PROPFIND”,“url”:"/remote.php/dav/uploads/USER/ac1fe18ffe6d2f0cb2105aec97f0b2c6",“message”:“Login failed: ‘USER’ (Remote IP: ‘ip’)”,“userAgent”:“Mozilla/5.0 (Android) Nextcloud-android/3.11.1”,“version”:“18.0.4.2”}
{“reqId”:“M3XIGguDKMdwJauBUFNZ”,“level”:2,“USERe”:“2020-04-30T09:13:46+02:00”,“remoteAddr”:“141.101.69.212”,“user”:"–",“app”:“core”,“method”:“MKCOL”,“url”:"/remote.php/dav/uploads/USER/b89b6631542bb083de05e277da57c1b6",“message”:“Login failed: ‘USER’ (Remote IP: ‘ip’)”,“userAgent”:“Mozilla/5.0 (Android) Nextcloud-android/3.11.1”,“version”:“18.0.4.2”}

thats the php log:

[30-Apr-2020 00:04:19] NOTICE: [pool www] child 9407 exited with code 0 after 16424.349025 seconds from start
[30-Apr-2020 00:04:19] NOTICE: [pool www] child 9907 started
[30-Apr-2020 00:04:52] NOTICE: [pool www] child 9390 exited with code 0 after 16458.631504 seconds from start
[30-Apr-2020 00:04:52] NOTICE: [pool www] child 10099 started
[30-Apr-2020 00:13:18] NOTICE: [pool www] child 9373 exited with code 0 after 16966.032368 seconds from start
[30-Apr-2020 00:13:18] NOTICE: [pool www] child 13114 started
[30-Apr-2020 00:23:03] NOTICE: [pool www] child 9413 exited with code 0 after 17548.165399 seconds from start
[30-Apr-2020 00:23:03] NOTICE: [pool www] child 16516 started
[30-Apr-2020 01:22:53] NOTICE: [pool www] child 9411 exited with code 0 after 21138.274916 seconds from start
[30-Apr-2020 01:22:53] NOTICE: [pool www] child 5271 started
[30-Apr-2020 01:53:34] NOTICE: [pool www] child 9368 exited with code 0 after 22982.410152 seconds from start
[30-Apr-2020 01:53:34] NOTICE: [pool www] child 16569 started
[30-Apr-2020 05:35:10] NOTICE: [pool www] child 16670 exited with code 0 after 35070.593047 seconds from start
[30-Apr-2020 05:35:10] NOTICE: [pool www] child 31535 started
[30-Apr-2020 05:43:23] NOTICE: [pool www] child 17253 exited with code 0 after 35458.825997 seconds from start
[30-Apr-2020 05:43:23] NOTICE: [pool www] child 2461 started
[30-Apr-2020 05:48:30] NOTICE: [pool www] child 16641 exited with code 0 after 35875.343280 seconds from start
[30-Apr-2020 05:48:30] NOTICE: [pool www] child 4292 started
[30-Apr-2020 09:35:43] NOTICE: Terminating …
[30-Apr-2020 09:35:43] NOTICE: exiting, bye-bye!
[30-Apr-2020 09:36:13] NOTICE: fpm is running, pid 837
[30-Apr-2020 09:36:13] NOTICE: ready to handle connections
[30-Apr-2020 09:36:13] NOTICE: systemd monitor interval set to 10000ms
[30-Apr-2020 10:31:31] NOTICE: Terminating …
[30-Apr-2020 10:31:32] NOTICE: exiting, bye-bye!
[30-Apr-2020 10:32:01] NOTICE: fpm is running, pid 818
[30-Apr-2020 10:32:01] NOTICE: ready to handle connections
[30-Apr-2020 10:32:01] NOTICE: systemd monitor interval set to 10000ms

is there another log that can tell me more?

apache error.log:

[Thu Apr 30 11:20:32.791675 2020] [mpm_event:notice] [pid 17740:tid 140105323871296] AH00491: caught SIGTERM, shutting down
[Thu Apr 30 11:20:43.064942 2020] [mpm_event:notice] [pid 19102:tid 139886496857152] AH00489: Apache/2.4.43 (Ubuntu) OpenSSL/1.1.1g configured – resuming normal operations
[Thu Apr 30 11:20:43.065091 2020] [core:notice] [pid 19102:tid 139886496857152] AH00094: Command line: ‘/usr/sbin/apache2’
[Thu Apr 30 11:20:52.139494 2020] [mpm_event:notice] [pid 19102:tid 139886496857152] AH00491: caught SIGTERM, shutting down
[Thu Apr 30 11:20:58.879973 2020] [mpm_event:notice] [pid 19306:tid 139622702824512] AH00489: Apache/2.4.43 (Ubuntu) OpenSSL/1.1.1g configured – resuming normal operations
[Thu Apr 30 11:20:58.880147 2020] [core:notice] [pid 19306:tid 139622702824512] AH00094: Command line: ‘/usr/sbin/apache2’

during the installation with this two guides my mysql server is crashed.
I was able to fix this issue by reinstalling the mysql server. The database will be untouched when using apt-get remove…
SOLVED