Missing diagrams from existing file's tabs

[Sudha Raghavan]

I am a consistent user of draw.io for years. 

Recently, I am missing the entire contents from a tab of an existing draw.io file that i have been using for months. the contents have been saved multiple times and the file re-opened.

I am not able to see version history option either. I am on 24.6.4 mac install

This is months of my work notes that I have lost.. making me thinking if I need to switch to another tool

Any help appreciated

[Michael Cropper]

On your document management system where you saved the file (i.e. Dropbox, SharePoint, Google Drive, whatever) - they usually have change logging enabled so you should be able to find your file and go back to a previous version. It's not really Draw.io's job to manage versions of your file. 

[Sudha Raghavan]

Appreciate the response
When I used draw.io in my prev company, I used to have  "Revision History" in file menu. 
I don't see that option in my current version. How do I enable it?

That option made me think it is draw.io that is managing version of file. 

[Michael Cropper]

It's not a feature I've personally used before so not sure. I've just checked my desktop installed version of Draw.io and I can't see that menu item, and I've just checked the online version which also doesn't have that version. On a quick Google I came across this which suggests that it's possible if using Confluence with the Draw.io plugin installed, https://www.drawio.com/doc/faq/confluence-cloud-restore-version

Either way, the previous comment is still the answer you're looking for. 

[draw.io Q&A]

The revision history dialog is available only when the file is saved to a storage that supports revisioning.