InvalidParameterException All files must have an owner!

InvalidParameterException All files must have an owner!

Please helppppppppppppp  Im running nuts.

I deleted a user in the databse and i started getting this problem..this happened yesterday and since then, when i go to members or user administration, it gives me this error "InvalidParameterException All files must have an owner!...ive done everything in the blog about the solution ie starting the crontrigger and enabling the garbage collector for 1 week...its still not working.

is there any way i can manually turn on the garbage collector...cos 1 week is too long!

I need some help plssssssssssss