Hello,
I have been trying to figure this issue out for 2 days. Basically I want to create a site collection from code using SelfSerivceCreateSite method, but it gives me the above errror. As I read in forums this methods usually refers to bad parameters being sent to the method, but if I use the same parameters but with SPWebApplication.Sites.Add() the site collection gets added. Self service site creation is enabled, the user has the proper right for self service site creation. I have decompiled the SPSite class and the SelfServiceCreateSite method internally calls SPWebApplication.Sites.Add and when looking in ULS the methods gets right about the time it call the method of SPRequest for creating the Site. Does anyone have any idea why is this happening or did you experience something similar? Any suggestion would be appreciated. Thanks