Please check some statements from this list and make some changes if necessary:
0. MS .net 3.5 has to be installed on your machine.
1. Turn off proxy in IE
2. Check if you are able to open
https://userarea.zennolab.com/en/login.aspx in IE
If you don’t get an access it means you got certificate's issue. Please install Windows updates for certificates, or add this one in trusted.
3. Try to run CapMonster.exe. In case it was opened fine - it is probably Phalanger issue. Reinstall Phalanger or ZennoPoster.
4. Check the date, time on your PC. It must be correct according to your GMT.
5. Check presence of security.dll in C:\Windows\System32
6. Try to turn off firewall, antivirus.
WARNING: We don't guarantee stable work on not official versions of Windows and VmWare workstations.