I've got Lightroom v 6.3.1 and have been using Lr for ages and it been working fine. On opening it up this morning it came up with a message saying "Updating - Lightroom needs to do some housekeeping". It then opens the app OK but as soon as I try to do anything with a photo e.g. export it after processing or access one of the menus it crashes. I've restarted the computer, I've uninstalled 6.3.1. and gone back to 6.3 but no joy (interestingly when I ran 6.3 for the first time it came up with the same "Updating - Lightroom needs to do some housekeeping". I'm on Windows 10 (and it's up to date - today), and have sent a error report.
Any ideas on what to do please?