Nextcloud 12.0.4, http error 500 after reboot

hi,

i have a problem, after reboot the VM of Netxcloud, the Putty-Login will work, but the Webinterface are white, an let me see the error HTTP 500.
the Webmin Interface of Port 10000 will show the login, but after the Login, will be the same error.
What can i do, will need help ASAP please.

the System are =
Ubuntu:16.04.3 LTS
Nextcloud: 12.0.4

so, have check is the Datanbase runing, bit here is the Problem.
what can i do?

Job for mariadb.service failed because the control process exited with error code. See “systemctl status mariadb.service” and “journalctl -xe” for details.
ncadmin@cloud:~$ systemctl status mariadb.service

 mariadb.service - MariaDB database server
   Loaded: loaded (/lib/systemd/system/mariadb.service; enabled; vendor preset: enabled)
  Drop-In: /etc/systemd/system/mariadb.service.d
           └─migrated-from-my.cnf-settings.conf
   Active: failed (Result: exit-code) since Mon 2018-02-19 19:57:15 CET; 1min 2s ago
  Process: 2804 ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS $_WSREP_NEW_CLUSTER $_WSREP_START_POSITION (code=exited, status=1/FAI
  Process: 2595 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR= ||   VAR=`/usr/bin/galera_recovery`; [ $? -
  Process: 2589 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
  Process: 2583 ExecStartPre=/usr/bin/install -m 755 -o mysql -g root -d /var/run/mysqld (code=exited, status=0/SUCCESS)
 Main PID: 2804 (code=exited, status=1/FAILURE)
   Status: "MariaDB server is down"

Feb 19 19:57:15 cloud.xxx.com mysqld[2804]: 2018-02-19 19:57:15 140713152235712 [Note] InnoDB: Removed temporary tabl
Feb 19 19:57:15 cloud.xxx.com mysqld[2804]: 2018-02-19 19:57:15 140713152235712 [ERROR] Plugin 'InnoDB' init function
Feb 19 19:57:15 cloud.xxx.com mysqld[2804]: 2018-02-19 19:57:15 140713152235712 [ERROR] Plugin 'InnoDB' registration
Feb 19 19:57:15 cloud.xxx.com mysqld[2804]: 2018-02-19 19:57:15 140713152235712 [Note] Plugin 'FEEDBACK' is disabled.
Feb 19 19:57:15 cloud.xxx.com mysqld[2804]: 2018-02-19 19:57:15 140713152235712 [ERROR] Unknown/unsupported storage e
Feb 19 19:57:15 cloud.xxx.com mysqld[2804]: 2018-02-19 19:57:15 140713152235712 [ERROR] Aborting
Feb 19 19:57:15 cloud.xxx.com systemd[1]: mariadb.service: Main process exited, code=exited, status=1/FAILURE
Feb 19 19:57:15 cloud.xxx.com systemd[1]: Failed to start MariaDB database server.
Feb 19 19:57:15 cloud.xxx.com systemd[1]: mariadb.service: Unit entered failed state.
Feb 19 19:57:15 cloud.xxx.com systemd[1]: mariadb.service: Failed with result 'exit-code'.

regards
simon

I put some of your logs in coding tags. Some messages are a bit cut, I don’t know if I did this, sorry in that case.

In general, we are no MariaDB experts, so we can only search for your errors. It would be interesting how you got into this situation, did you do a hard reset (so that possible database actions were interrupted)? If found a few references to the /var/lib/mysql/ib_logfile1 logfiles (some suggest to delete them, if you remove them from this folder, keep them somewhere else). Try to do a snapshot of your VM before doing anything so you can go back to the current situation.
Review your innodb-settings, especially if you have tuned them a lot.