Microsoft .NET Framework 3.5 SP 1 is required in order to install and run Micro Focus Rumba 8.0 software. This feature is turned on by default on Windows 7, but some administrators might turn it off if they don’t use them. The users will encounter this error message if administrators turn off .NET 3.5.1 Framework feature on Windows 7 after Rumba 8.0 is installed. Perform the following steps in order to turn on .NET 3.5.1 feature on Windows 7:

Click the Start button -> Control Panel -> Programs, and then click Turn Windows features on or off.  If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

Select the check box next to the Microsoft .NET Framework 3.5.1 option and click OK. This will turn on .NET Framework 3.5.1 feature on Windows 7. Restart the computer.
You should be able to launch Rumba successfully.
Note: Please contact Micro Focus SupportLine if the problem still continues.