Sometimes i recive:
SIP 500 - Server Internal Error
temporary failure
Hello,
This issue is not caused by Zoiper. It is only showing the error that is sent by the server. Please report the issue to your provider.
i get this error alot and would really like to know more about what is happening. oftentimes i'll just keep getting this error until i reboot the phone, then it works. so it doesn't seem likely to be an issue with my provider.