Hi

I have the same problem here. Updated Virtuemart from 3.8.4 to 3.8.6. When using Chameleon Rules to set VirtueMart shopper groups, we see this message in Joomla frontend:

JUser: :_load: Unable to load user with ID: -1

It seems this originates from /plugins/chameleon/virtuemartrules/virtuemartrules.php line 108:

$usermodel->_id = -1; // invalidate so the getUser does not return previous cached value

Apparently VirtueMart behaviour changed in version 3.8.6 and setting _id to -1 now results in getUser()->virtuemart_user_id also being -1! I resolved this by adding a version check for this line:

if (version_compare($version, '3.8.6', 'lt')) {
  $usermodel->_id = -1; // invalidate so the getUser does not return previous cached value
}

Stephen, could you have a look at this and include a fix in the next release of Chameleon?

Thanks a lot, best regards,
Stefan