Cannot open existing collections

I use the extension constantly and also told my friends at work to use it so instead of passing them a bunch of links relating to assignment, I just export to them the collection.

One thing though, sometimes when I try to open existing collections it gets stuck and nothing is open. In order to solve it i have to reopen each link in the collection, recreate the groups and then save the collection again.

Raising to your attention if you can check.