My customer reported me, that he can't log in to shop because he's s getting almost blank page:
I tried to log in as customer using my account and had no problem with this. But my customer was saying the problem is still there. So I asked him about his login and password. When I tried to log in using his credentials I had the same error. I noticed when I press "Log in", cpu usage of MySQL goes to 100%.
What could be wrong? There must be some kind of problem with account, but I have no idea how to debug it.