I keep on loosig edited files from LR

Sounds like you may misunderstand how Lightroom works. If you can find the original files, then you have found what Lightroom uses. Lightroom edits those files “non-destructively”. That means that the edits are not applied to the pixels of those files, but stored in the catalog as a kind of ‘to do list’. Consequently, if you open the file in another application, you won’t see the edits. If you want to have an edited file outside of Lightroom, then you must use ‘Export’ to export an edited copy. You can choose different file formats, such as tiff or jpeg.

Unfortunately you haven't given us any detailed infos about your issue and about your system. Therefore, all proposed solutions are a look into the crystal ball

Please describe more detailed what you’re doing and what happened.

Do you get error messages?

Do you work with the correct catalog?

It can be a corrupt catalog. Try to restore the catalog from the recent backup. Or try to create a new catalog and try the functionality with several images.If it’s work you can import the images from the “old catalog”. 

Please provide a copy of your 'System Info'. This can be get from the Lightroom menu item Help > System Info. There's a copy button in the System Info dialog. Press this button and paste the info into a text file and attach it to your next forum post.