LIGHTROOM - PREVIEWS NOT SHOWING

[pjy86534130]

Photos taken on 5d3, all lightroom and raw up to date. But for some reason, in the develop panel below, the raws all appear blank, but only appear one at a time if I click on one. I don't think thats ever happened before. My preferences look the same, any ideas.

ps My screen looks like the grey one here  https://community.adobe.com/t5/lightroom-classic/lightroom-cc-library-module-no-longer-showing-thumb...

 I did the monitor calibration thing and it didn't change.

[pjy86534130]

ok i deleted the lr.lock file and now theyre showing,

[JohanElzenga]

Do you see no thumbnails in the Library module (that is what the screenshot in the linked thread shows)? If so, your previews cache could be corrupted. Open your catalog folder and remove 'catalogname previews.lrdata' from it. Then start Lightroom. Initially you still won't see any thumbnails, but then Lightroom should start rebuilding them and so they should appear one by one.