Can't open "Shop" and can't add new "Product"

[FullTopMan]

Joomla Version 1.5.25
VirtueMart 2.0.0
After installation, can't open "Shop" and can't add new "Product" (Administrator console): error "The website cannot display the page"
Address for "Shop" http://www.sitename/joomla/administrator/index.php?option=com_virtuemart&view=user&task=editshop (and error "The website cannot display the page")
Address after click "New" in page "Product" http://www.sitename/joomla/administrator/index.php (and error "The website cannot display the page")

What could be wrong?

P.S. Reinstall Joomla and VirtueMart. Tried different versions of Joomla. Does not work.

[John2400]

Try logging it to the back end and chaning the template ? back to default.

Also I think you migh update the VM - to the latest?

This has happened to some

[FullTopMan]

Resolved.
I check log for my hosting management system (based on Parallels) and view PHP Fatal error: Allowed memory size of 16777216 bytes exhausted (tried to allocate 32768 bytes) in /var/www/vhosts/mysite/httpdocs/joomla/libraries/joomla/language/language.php on line 353
After that i download and applied "Memory Limit Plugin for Joomla".
Error is gone.