It is funny, but after installing the new version 4.2 it is not possible to enter a valid access code anymore.
I tried it with Linksys PAP2, Linksys Phone and Counterpaths BRIA. -->> NO SUCCESS.
Just overwriting the installation with the 4.11 version it works again as before.
At that point I am asking, why NCH licence expires after 3 months to upgrade even there are only bugfixes done and no essential function added?
Even at Microsoft I can install service packs after years to solve errors in the software.