Problem logging into administration panel

[3mpetri]

Hello! I'm a beginner in CMSMS, and have just set up a web on it for one of the clients - 1.11.7 “Genovesa”

Both me and them can log in into admin panel from anywhere EXCEPT from their office building. Once trying to log in it just outputs an php error. They are using IE9, but I've also tried logging in from IE9 from other locations and it works.

Further on, they CAN log in into CMSMS admin panel of another site.

Mistery..

[velden]

What about posting the php error to start with?

[staartmees]

Possible his office blocks external websites?

[3mpetri]

Ok, scratch that php error, it is actually this upon every login:

Not Found
The requested URL was not found on this server.

Just got a screen shot from the client.

[3mpetri]

Possible his office blocks external websites?

Firewall was first on my mind, but then it wouldn't allow access into admin panel from another site too, right? (it is hosted on different server though)