after ignition update/module installing any opened designer requires to be restarted.
it asks if i want to export the project to a local file or if i want to leave changes.
i told it to export project, it showed the export window BUT designer was restarted immediately. my workmate lost several hours of designing 
So, you were not able to save the file? I bet it is in the downloads or my documents folder. It should be a .proj file.
there i searched for it but nothing
What version of Ignition are you running?
it happened yesterday with the latest and some hours before with the one before.
Is this all happening on the same computer, or is it occurring across multiple computers? Also, are you able to reproduce this problem?
it happened on 2 computers: the first time adding an external module and the second upgrading the software with a deigner opened.
tomorrow i could try to replicate it by removing a trial module and re-adding the same module.