How many images are you using. I find it works well with just two. I shoot three exposures on a tripod (standard +2ev and -2ev) and use the last two bracketed images. LR usually produces a good photorealistic (not tone mapped) image.
I am seeing that same issue where sometimes HDR justs sits there and the bar never moves. I just restart LR and it usually fixes the issue. Sometimes I have to restart the computer.
Also please try this
Go to Edit -> preferences -> file Handling (Windows) Lightroom -> Preferences(MAC) -> file Handling
1.) Click on Purge cache.
2.) Change the size of Camera raw cache settings -> maximum size to 30 GB
Close Lightroom and reopen it.
Try what you were doing before.
Please let us know if you are facing the issue again.
thanks. I tried but nothing changes(even with two immages) (It happens with all of the immages not just with one)When I push purge cache nothing happens (no charging bars or other)...30 gb max dimension done and restart Lr...nothing happens