can't open back office site.

[Ly Con Sao]

Hi

Can you help me please

I use PS 1.4.1

Yesterday, I can still log-in the back office area. Now I try to open the back office area and get the error message
Unable to connect: FireFox can't establish a connection to the server at wp10630804.wp269.webpack.hosteurope.de.

This is the second time this occurredd, I think this error occur because I activate the SSL, or I need set a htaccess file.

I want to ask is there any solutions, which I don't need to reinstall whole system.
or how can I deactive SSL by change some values in config files

Please help me, thank you.