LOGINERROR] Unknown error at login server (2)

what cause of the error? this happened to my 3rd account only, the first and second accounts were fine.

all three accounts are maxed level 110 and played for 2 weeks then BAM! this happenned yesterday.

You are not talking about your own server, I assume.
Which server are you playing at? Inform yourself about their conditions, like, if they have IP- or HWID-Limits.
If there are some, you know the issue and why this "error" keeps happening.

It's a russian server, eridos sro: [Only registered and activated users can see links. Click Here To Register...]

i dont speak russian so im not sure how i can ask their gm for help, the reason i play there because of low ping.