I was having a match in the test version against the AI.
I haven't used any cheat during the game and the situation was this
just before the AI's move
Then i got this error page:
Fatal error: Cannot access empty property in /var/www/arcomage.net/public_html/_/test/core/Db/Game.php(745) : eval()'d code on line 5
Seems like, after playing "dream shift", it attemped to summon a non existing card (745).