Double clicking a Calc file would not start in Ubuntu 14-04

I have recently migrated to Ubuntu 14-04 from 12-04.
When I try to launch Calc, he first tries to restore non saved document. I have 2 of them. One fails the second is ok. So I get this screen


Then I click on the done button and Calc doesn’t start.
I have tried several time, the failed documents stays as failed and I am still not able to start Calc.
Any Hint?

Click Cancel [Annuler] instead. This should break out of the recovery process.

Actually did try it but with no better result…
There is probably something corrupted with the first file. Is there any way to manually remove this backup file so that Libre office thinks it never existed?

Try and locate the file of the same name with a leading tilde (~) and delete it. Also have a look in backup/ under the user profile.

backup was empty. I deleted some files and lock starting with tilde but with no real success. I finally solved the problem by removing libreoffice installation and reinstalling from scratch…
At least it works now.