An already working Piwik installation could not be Updated due to a mysql error. Several Updates went right but not it crashed.
Complete empty Database or complete new installation with old and new databases did not work ether.
Special Characters in the MySQL Password are saved as HTML-Encoded.
So instead of a "" in my password an "& s e c t ;" (without the spaces) was written in the config file.
Attachment: bad replacement of special charackters in password
Thanks for the report. Also reported in: https://github.com/piwik/piwik/issues/341
In fc2718d880c37f4fd91fa4824b3b956d6326e1c0: refs #5409 #341 #5349 if a config value contains a dollar sign convert it to an html entity to prevent it being interpreted as a PHP variable. This allows us to remove the RAW ini parser flag which causes trouble on some PHP versions as the parser seems to be buggy.
In dea3e06134c54116171d73ef72d48b6d2a7f330a: refs #5409 make sure a group is set