Sync folder and importing doesn't work anymore

I don't know what happened with LR 5.4 but lately LR won't keep track or sync with changes that I have made to a folder. For instance, I usually shoot RAW, make my changes and then convert all files to jpeg then delete all the RAW files.

Once this is done, many RAW files are not deleted while many JPEG do not show in LR folder but exist in the Mac finder folder.

When I try to Sync the folder, LR will tell me that there are X amount of photos to sync, When I click import it will say 'Importing files..." and nothing will happen until i quit the process.

Any ideas?

Thanks

Mica