TOPIC: Getting 403 Error

I have J1.5.14 with JomSocial for registration and AEC for membership. Currently the registration works fine. I have done a first time install of DT Register and JEvents. Configured JEvents no problem, watched videos... When I click on create New Event I get a 403 - You are not authorized" error message. I have all the plugins published and all SEF turned off.

Can someone please help me get this installed?

Thanks in advance.

Update:

1. I have upgraded Joomla from 1.5.14 to 1.5.15
2. I have removed all SEF
3. I have uninstalled AEC
4. Remaining configuration JomSocial, JEvents, DT Register (which are supposed to work together.
5. I have disabled the Legagy plug

I can now create an event since I added two users. But I can not create an account or login, I get a 403 error.

Can someone help me try to get this thing installed?

Thanks in advance.