Can´t access the wordpress themes or plugins

Hi there,
I installed wordpress freshly on my webspace and now everything is running perfectly except i cannot access themes/plugins/etc. from the wordpress community in the dashboard. It says:

An unexpected error occurred. Something may be wrong with WordPress.org or this server’s configuration

so i am wondering what the problem can be, because actually the database should be alright..

Any ideas?
Thanks in advance…
Florian