not able to access a resource on the server

HI all

I work in an multi site environment (main office + 8 sites) all connected in
the same way with VPN’s (watchguard firewalls)
Only one site is not working properly,
Explain: on the site location PC I map a drive of a WS in the “main office�
and it works fine, but when I do in on one of the server the local computer
cant access it (I see the drive in “my computer� but I can’t access it)
Also I can’t open my outlook he is trying to communicate with the exchange
server but cant

I flashed the local FW and rebuild the tunnel but still the same symptoms
are back

Please if any one have any direction
I will appreciate it

Ilan