[Linphone-users] Warning: Could not start UDP transport on port 5060, ...

[K.Kong]

I am using the Windows version of linphonec.  When I start the program, I get:

Warning: Could not start UDP transport on port 5060, maybe this port is already used.

When I make a call, I get:

Error from linphone_core_invite

I Googled and it seems nobody has gotten this error before.  What could be the cause?  Any help appreciated.

Thanks.