Edit/Add Product in Admin gives 500 error

[zainabubu]

Hello,

This is a pretty random error that recently came about. I use vm 2.0.26d + joomla 2.5.20. I have been able to access my virtuemart back end fine, and I did a few quantity edits last monday. On Friday, I clicked on a random item to edit some detail and got a "500 - An error has occurred.
Method getErrors not defined" I've checked my error logs and nothing is recorded there to help explain this problem. My most recent edits to database has been to update csvi-pro and added Nextend Smart slider 2.
Help would be appreciated.