Question: I had created a .vsd file in Visio Premium 2010, saved it, emailed a copy to my colleague. Couple of days later, I reopen it, only to find that for some reason, it no longer treats the the document as a UML template-based document.

As a result of this, I cannot do *any* edits on the file. Any ideas as to why the UML info gets discarded? 

Is there any workaround so that I can edit the file? How can I make Visio think into believing the file is based on the UML template?

Note:

* Copy + paste from the existing file to a new one is not practical because there are 18+ tabs and Visio seems to discard all names and other meta-data information on pasting.
* I've created a new diagram using the "Create New From Existing.." dialog, doesn't help, it's still the same issue.

Answer: 
First step : Go to Photoshop –> Preferences –> File Handling settings, and set both Maximize Compatibility and Image Previews to checked.

If that does not help, the article [FIX: Quick look on OSX not working (black box)](http://www.hamleshmotah.com/index.php/2010/01/14/fix-quick-look-on-osx-not-working-black-box/) suggests two solutions:

1. Select Utilities > Disk Utility, and then "Repair Disk Permissions". You will have to boot from the install media if you are repairing the same drive that your system boots from.
2. Reinstall the Mac OS X Update.
This worked for me. In Photoshop - Preferences - File Handling - DISABLE COMPRESSION OF PSD AND PSB FILES. I guess Finder doesn't like decompressing saved files to make a preview. It's funny though, I already do save with all preview images. But they barely work and usually fade out right after they appear.