Error on adding new coupon

[uncanny]

I'm unable to add any coupons in the backend.

I'm running 2.0.18a on joomla 1.5.26

These are the errors I'm getting when I click "NEW" coupon
[10:43:25.776] POST http://ceogaming.org/administrator/index.php [HTTP/1.1 500 Internal Server Error 953ms]
[10:43:26.708] The character encoding of the HTML document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the page must be declared in the document or in the transfer protocol. @ http://ceogaming.org/administrator/index.php


Basically, the resulting page just goes blank

[PRO]

are coupons enabled in the vmart configuration?

[uncanny]

yes, coupons are enabled in the config panel

I'm also getting these errors on the logs on from my server:
[Sun Mar 03 11:03:19 2013] [error] [client 75.73.53.247] #3 /home/ceogamin/public_html/libraries/joomla/application/component/controll in /home/ceogamin/public_html/administrator/components/com_virtuemart/views/coupon/view.html.php on line 89, referer: http://ceogaming.org/administrator/index.php?option=com_virtuemart&view=coupon
[Sun Mar 03 11:03:19 2013] [error] [client 75.73.53.247] #2 /home/ceogamin/public_html/administrator/components/com_virtuemart/helpers/vmcontroller.php(146): VmController->display(), referer: http://ceogaming.org/administrator/index.php?option=com_virtuemart&view=coupon
[Sun Mar 03 11:03:19 2013] [error] [client 75.73.53.247] #1 /home/ceogamin/public_html/administrator/components/com_virtuemart/helpers/vmcontroller.php(118): VirtuemartViewCoupon->display(), referer: http://ceogaming.org/administrator/index.php?option=com_virtuemart&view=coupon
[Sun Mar 03 11:03:19 2013] [error] [client 75.73.53.247] #0 /home/ceogamin/public_html/administrator/components/com_virtuemart/views/coupon/view.html.php(89): DateTime->__construct(), referer: http://ceogaming.org/administrator/index.php?option=com_virtuemart&view=coupon

but nothing in the joomla log.

[PRO]

is there a reason why you are using J1.5 ??

[uncanny]

Can't say. I didn't create the site. I'm just helping someone out with some updates.

[PRO]

Can't say. I didn't create the site. I'm just helping someone out with some updates.

the problem probably stems from using J1.5

1.5 support has ended from Joomla

BUT!

have the coupons ever worked on this site?

[uncanny]

VM was only just installed so I can't exactly say. They technically have never worked I guess. Maybe this'll help push for the site to be upgraded to 2.5.

[PRO]

go to 2.5  if its a new site.