:o
I had hundreds of products across dozens of categories. They are all now gone. I have no products. I have no categories.
What did I do? I went into virtuemart Configuration => Language Settings => Multi Lingual Shop, and selected English (there was nothing selected before.)
I have tried to unselect it, but it can't be done. All my data is wiped out. I've gone into phpMyAdmin and repaired tables... no luck.
Virtuemart 3.0.10
Poking around in the database, I can see that the categories are listed in a table called: virtuemart_categories_en_us
So they are still there, but virtuemart doesn't see them for some reason?
OK. I got my products back, but WOW, what an unexpected disaster/detour. Here's the solution:
I went into the database and found the table called virtuemart_configs. I edited it... it has virtually all of your VM settings is a massive text file. one part of the text file says "active_languages=["en-GB"]" I tried deleting that. Didn't work. So I edited it and changed it to "en-US". All of my categories and products came back, I think.
in the admin was there two "English" i.e. gb & us? Is it a labelling problem?
This is also described in the manual
http://docs.virtuemart.net/manual/general-concepts/218-installation-updating.html
and a FAQ http://docs.virtuemart.net/faqs/113-products-vanished.html