Only two days after releasing 6.0.1 we already have to do a new patch release, with a big Mea Culpa from the core team. As mentioned in the 6.0.1 release blog post, we fixed some problems in the document type editor that popped up in the 6.0.0 version. Unfortunately, the upgrade script for 6.0.1 was not entirely correct and caused tabs and/or properties to disappear from your document types.
If you've put a property on an inherited tab, the upgrade from 6.0.0 to 6.0.1 would have caused problems for you.
So let's say you have a "Page Settings" document type, with a tab called "Navigation". As a child document type of "Page Settings" you have "Homepage". If you've put one or more properties on the "Navigation" tab on the "Homepage" (inherited from "Page Settings"). See the picture below (click it for a larger version):
What can you do to fix?
Unfortunately, some properties and tabs might have gotten deleted. We hope you've used the usual precaution and made a backup of your database. Make sure to restore the database in which your document type structure was fine (the 6.0.0 version). The installer of the 6.0.2 version will now properly upgrade your database without deleting properties/tabs.
We're very sorry that this has happened. We were focused too much on making sure that document type editing worked as expected in 6.0.1 and didn't pay enough attention to people who were upgrading. For future releases we'll make sure to test the upgrade path thoroughly as well.
For this 6.0.2 release we've upgraded a bunch of sites that were previously affected and they all worked as expected after doing the upgrade from 6.0.0 to 6.0.2.
6.0.2 is available from CodePlex and NuGet now!