Both computers running Windows 7 and both using Teamviewer v7 (my laptop has the latest one 7.0.14484, my mom's desktop has the previous one 7.0.13989).
I could not reach the partner computer (my mom's pc) because of this issue and my mom is out for a week.
This issue occurred the first time a week ago. After my mom restarted her computer I was able to connect to it, but a few hours laterit failed again.
I have tried from another computer to connect to it without success.
1. go and input partner ID and select Remote desktop option
2. hit the "Connect to partner" button
3. input password
The TeamViewer window minimize,
Then after about a minute it displays the pop up "This was a free session ...." and drops back to ready to connect.
The other pc is online (I could see it on Skype).