Cannot upgrade to version 16.0.0 (RuntimeException: A handler is already registered for user)

#1

Hello,
I like to upgrade my nextcloud installation from 15.0.5 to 16.0.0.

When I run the command “php ./occ upgrade” I get the following massages:

nginx@server /var/www/xxx/htdocs/nextcloud $ php ./occ -vvvv upgrade
Nextcloud or one of the apps require upgrade - only a limited number of commands are available
You may use your browser or the occ upgrade command to do the upgrade
2019-05-14T19:49:26+00:00 Set log level to debug
2019-05-14T19:49:26+00:00 Repair step: Repair MySQL collation
2019-05-14T19:49:26+00:00 Repair info: All tables already have the correct collation -> nothing to do
2019-05-14T19:49:26+00:00 Repair step: Repair SQLite autoincrement
2019-05-14T19:49:26+00:00 Repair step: Copy data from accounts table when migrating from ownCloud
2019-05-14T19:49:27+00:00 Repair step: Drop account terms table when migrating from ownCloud
2019-05-14T19:49:27+00:00 Updating database schema
2019-05-14T19:49:27+00:00 Updated database
2019-05-14T19:49:27+00:00 Updating <files_external> ...
2019-05-14T19:49:28+00:00 RuntimeException: A handler is already registered for user
2019-05-14T19:49:28+00:00 Update failed
2019-05-14T19:49:28+00:00 Maintenance mode is kept active
2019-05-14T19:49:28+00:00 Reset log level

I hope I will find here some help for this problem.

Daniel