Originally Posted by Hans
Due an old MySQL bug, which do still exists it was necesarry to remove the "_". For this reason, with the introduction of ISConfig 2.2.20 the "_" has been removed for new databases. This modification does not affect existing databases.
If you only can create one MySQL database, probably you should increase the value from 1 to a higher value or -1 on the basis tab of the site within ISPConfig.
I set number of databases to 3 ( -1 is not awalable) but ispconfig still offer only:
Database Name: web1db1
Database User: web1u1
when I want create new database (and web1db1 exists).