Upgrade to 20.0.7 didn't work

[bb77]

I found this topic regarding to your issue:

[SOLVED] Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes

ERROR MESSAGE: An exception occurred while executing ‘ALTER TABLE [TABLE_NAME] CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_bin;’: SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes SOLUTION: $ sudo mysql -u root -p MariaDB [(none)]> use nextcloud; MariaDB [nextcloud]> set global innodb_large_prefix=on; MariaDB [nextcloud]> set global innodb_file_format=Barracuda; $ sudo -u www-data php occ maintenance:repair

The instructions that most likely will solve the issue, are right in the first post.

Hope that helps.