VMWare is a great virtualisation tool for running various operating systems and appliances without the need to physically install them on a separate hard drive or partition.
But, as every piece of software, VMWare Player has it's problems, too.
Error while powering on -- internal error
When I tried opening any of the saved virtual machines in VMWare Player's library, the above error message appeared.
The solution
The solution is quite simple. Maybe too simple for you to believe it works.
- Close any of the running virtual machines and exit VMWare Player.
- Go to the folder where VMWare Player is installed.
- Find the executable 'vmplayer.exe'.
- Rename it to something else, for example 'vmplayera.exe'.
- Rename it back to 'vmplayer.exe'.
- Try running any of the virtual machines again.