This has been happening to me for the past few weeks. If I close my LR5 program and try to re-open the catalog I get a error message that says
Lightroom cannot use the catalog named "Lightroom 5 Catalog 2014" because it is not writable and cannot be opened.
This could be caused by incorrect permissions or because another Lightroom application is using the catalog. You may try to correct the problem or you may select a different catalog.
Then I have the option to choose a different catalog / try again / Exit
I have to go to the backup every time. I am currently working in Windows 8.1
Retrieving data ...