Problem to Install 11.0.1 - Failed to enable app twofactor_backupcodes

[JohnBluebear]

Hello, I use an 1und1 Webhosting Domain with:

PHP Version: 7.0.14
Memory Limit: 512.0 MB
Max Execution Time: 3600
Upload max size: 2.0 GB

Type: mysql
Version: 5.5.52

and Nextcloud 11.0.0.

If I start the update zu 11.01. there is an error like "twofactor_backupcodes: Failed to enable app twofactor_backupcodes".

What is to do?

[nickvergessen]

It looks like you restored a backup without clearing the database before the restore.
Therefor Nextcloud thinks that an app is not installed, although it is already installed.

If you are sure this happened, open lib/private/Installer.php:
find:

				throw new HintException(
					'Failed to enable app ' . $app,
					'Please ask for help via one of our <a href="https://nextcloud.com/support/" target="_blank" rel="noreferrer">support channels</a>.',
					0, $e
				);

replace with:

				OC_DB::updateDbFromStructure("$appPath/appinfo/database.xml");

and try again.