Getting an error page after confirming order

[billo007]

virtuemart 2.0.18a
Joomla 2.5.8

After clicking the confirm order button, thank you page does not load goes to blank page screen shot attached.

[attachment cleanup by admin]

[jenkinhill]

If your server does not support SSL (https) and you don't have a valid security certificate then turn off "Enable SSL for sensitive areas (recommended)" in Configuration/Shop

[billo007]

I have a valid ssl certificate everything was working fine before i installed sh404sef. Everything else is working good. the domain is
http://aubouquet.ca

[jenkinhill]

So it works without sh404sef? Then you know where the issue lies.

VM2 works very well with J2.5's inbuilt SEF functions, but ISTR others have also reported problems with 3rd party SEF components when using SSL. Maybe Yannick can help on http://anything-digital.com/