I did as you asked , I deleted the TMP folder and the problem is still occuring.
Too bad, I hoped it would have worked
Well, it seems that your coollection has been corrupted somehow, and you'll have to restore your last automatic backup:
1) go again to the folder "My Documents\Coollector".
2) this time, go into the folder "Backups", where are all your automatic backups.
3) double click the latest backup (the one with the biggest number, for instance "MyCoollection17.cool").
If even the backup doesn't work
please reinstall Coollector (no need to uninstall before).
But if this backup works fine
you'll have to replace your default coollection file with this backup:
4) rename the default (corrupted) coollection file "My Documents\Coollector\MyCoollection.cool" into "My Documents\Coollector\MyCoollection.corrupted.cool".
5) copy the latest backup into "My Documents\Coollector". Now you have "My Documents\Coollector\MyCoollection17.cool".
6) rename to remove the number "17", and make it "My Documents\Coollector\MyCoollection.cool", that is the default coollection which will be used when the program is launched.
7) please mail me "MyCoollection.corrupted.cool" so I can have a look at it. My email address: hector at coollector dot com