Temporarily Unable to Repair Corrupt Catalog message - how to fix?

[AdamfromCanada]

I've been using Lightroom for ages with no issues.  I have version 5.7.1, working with a PC.  The last couple of weeks, Lightroom was crashing and saying there was an issue with the preview cache.  I googled and the solution I found was to delete the previews.  I did that, and it seemed to work at first.  It crashed last night but after I'd been working for a pretty long time. 

I then tried to open it today and it is unable to open.  The message it gives is titled "Temporarily Unable to Repair Corrupt Catalog".  The dialogue below says "Lightroom encountered problems reading or writing from disk when attempting to repair "Lightroom 4 Catalog 2-2"  The repair operation may succeed in future attempts.  If you wish to try again, please first check available disk space and close all other applications."

I've tried several times now with the same result.  Nothing else is open, and I've tried rebooting my computer too.  I can't access my catalog.  I'd appreciate any help.

Thanks!

[Mohit Goyal]

Hi adamfromcanada,

Please refer the below related discussion and check if that helps.

Urgently need help repairing Lightroom 6 catalog 'Lightroom encountered problems reading or writing ...

repair catalog multiple times

Regards,

Mohit

[AdamfromCanada]

The second thread you referred me to is not answered.  The first just says it may be my hard drive.  Now, I haven't been having other issues, so if it's the hard drive, that's bad news and something I'll need to address immediately, but changing hard drives seems an extreme first step unless there's some strong evidence that that is the cause. 

In the meantime, I've successfully opened a back-up, but it loses me a couple days of work to return to that and I'm worried that the corruption could happen again - after all, I hadn't added anything new in the last couple of days. 

Is there anything else I can try?