Skin file "skin" not found

Hi there,
I installed C7.5 64bit today. It ran fine. Then I re-instaledl Halion 5 and Groove Agent 4 both on 64 bits as well. But after that, I got that message when trying to start 7.5 64 bit AND ALSO 7.5 32 bit ¡¡¡¡ So, basically, I have none of them working ¡ I ran a maintenance to e-licenser, but did not help.
Please, help me, I have work to finish and I am halt here ¡¡