"2\unins000msg" error

I can't get rid of the error message.
I tried to install a new Spybot on top of the current one but a warning message pops up and won't let me continue with the installation.
It seems to load fine, but at some point "2\unins000msg" reappears and the program stops loading.
How do I get rid of the error message?

Hello Erinaceous,

2\unins000msg is the uninstaller.

Please open a support ticket here

Best regards,
tashi