If the following error: "Undefined index: name in system_requirements() (line 39 of ..." occurs in your Drupal environment (status page, errorlog or whatever), here's the solution how to fix it:
It seems that there is a problem with old install profiles:
Search for the name of your install profile (can be found in the "Status Report", Second line of the table) in the DB "system"-table and set status to "1" for it!
Or via SQL (check the name before!)
UPDATE system SET STATUS = 1 WHERE name = "YOUR_INSTALL_PROFILE_NAME";
YOUR_INSTALL_PROFILE_NAME may be replaced by "custom", "demo_profile", "commerce" or whatever you used to install your site!
Another solution is described here, but I think it does not solve the problem but just the message and requires to hack core (UGLY!): ;)