Cannot allocate categoreis

[ukfish1]

Joomla 3.9.16
VM: 3.6.10

I am trying to update all the prices on our site but there is a problem with the product categories selection. It now permanently says "do not store" and won;t let me slect5 a category. If I change the price and save the products it doesn;t allocate the product to any categories.

Any ideas why this is happening.

Thanks Paul

[jjk]

Perhaps something similar to this:
http://forum.virtuemart.net/index.php?topic=141618.0