Hey there VM team. I found solutions for this problem for older versions. But I believe some thing have changed since those threads.
What happened. My client got click happy and clicked the AIO upgrade before upgrading VM. After doing so, Virtuemart disappeared from the component list.
What I have done:
1. I accessed the VM component using a direct link: /administrator/index.php?option=com_virtuemart and upgraded VM to 2.0.20 from the previous version.
2. I checked myprefix_extensions and virtuemart is still set to enabled 1.
3. I checked myprevix_menu and changed the ID of COM_VIRTUEMART to match that of myprefix_extensions/virtuemart.
4. I tried changing published of myprevix_menu/COM_VIRTUEMART to 1.
5. I don't have Xmap installed.
6. Ran "Install or if necessary update tables".
None of the above had any effect. I have emptied both system and browser cache. Ideas?
Don't know if this helps:
{"legacy":true,"name":"VIRTUEMART","type":"component","creationDate":"March 17 2013","author":"The VirtueMart Development Team","copyright":"Copyright (C) 2004-2012 Virtuemart Team. All rights reserved.","authorEmail":"max|at|virtuemart.net","authorUrl":"http:\/\/www.virtuemart.net","version":"2.0.20b","description":"","group":""}
I am having the same problem, but my site is a fresh install of virtuemart 2.0.20. I followed the install instructions, installed component, then aio installer, and the virtuemart component is NOT LISTED in the component dropdown menu.
If your fresh virtuemart installation doesn't work, you probably somehow messed up the installation folders/installed component information in Joomla. If nothing else helps, try this: http://docs.virtuemart.net/tutorials/30-installation-migration-upgrade-vm-2/98-possible-virtuemart-installation-problems.html
Following that procedure should delete any remainings of VirtueMart from unsuccessfull install/uninstall attempts.
In my case nothing worked. I had to restore from an earlier date.