YamiKaitou, thank you!
A few days ago I was installing a TS3 inactive channels delete bot in the NEXT folder to hlstats web folder so I unknowingly accidentally overwrote config.php of HlstatsX:CE.
When I was overwriting web files I have overwritten every file, except config.php, because I didn't want to fill out the username/pw/dbname again.
SOLVED.
Thank you all again.