The DEB package version 5.2.16 installes without a problem. After the start an empty window is opened and in a dialog box it is showing an Error executing process.
Starting zoiper5 executable on the command line I see the problem. The file libGLESv2.0.so cannot find. It is expected on /usr/local/applications/Zoiper5/swiftshader.
There are errors because of this: Unable to move cach folder GPUCache to old_GPUCache_000, Exiting GPU process due to errors during initialization and Shader Cache Creation failed: -2.
If I click on Close in the Box Error executing process in the terminal the sames errors are printed again. Six times, then the ZoiPer welcome screen is shown.
Closing the program is not possible. It stays open. I have to kill the process zoiper.
I earlier had downloaded 5.2.4 or 5.2.6. With that version this problem does not occur. But with this older version there was an error with a wrong named library as dependency. Therefore I had to install witch dpkg --force-all.