Catalina Deleting Previous Time Machine Backups?

[Dipsea]

My previous TM backups have disappeared as follows:

• I installed Catalina Beta 3 over Mojave on 7/14.
• After discovering that my copy of Photoshop CS5.1 would not run because it needed a legacy version of java, I spent several hours trying to find a workaround for the fact that Catalina would not let me install that. I decided to install the most recent Catalina to see if that made a difference.
• I installed Catalina Beta 4 on 7/21.
• No luck. While Catalina Beta 3 did not warn that Photoshop CS5.1 would not work, (trying to run that app prompted the java warning from Photoshop), trying to run Photoshop under Catalina Beta 4 now prompts the following from Catalina "You can’t use this version of the application “Adobe Photoshop CS5.1” with this version of macOS."
• At this point I gave up and decided to restore Mojave from a TM backup. This is when I discovered that all of my TM backups prior to installing Catalina Beta 4 are gone. The TM disk is a 2TB external USB drive. I have often verified and occasionally used those TM backups.

My question is, would Catalina really have deleted all of my previous TM backups or is it somehow just not showing them? In either case, is there some reasonable way I can get back to Mojave?

Thanks for any ideas.

 

[madrich]

If you are trying to look for your TM backups (created under Mojave) with Catalina you cannot see them because it is a different operating system from Mojave. I would restore your OSX back to Mojave and then turn on the TM to see your prior backups.

 

[Dipsea]

If you are trying to look for your TM backups (created under Mojave) with Catalina you cannot see them because it is a different operating system from Mojave. I would restore your OSX back to Mojave and then turn on the TM to see your prior backups.

[doublepost=1566768333][/doublepost]Unfortunately, one needs the Time Machine backup to restore to Mojave.

 

[KALLT]

How large is your TM volume and how many snapshots did you have? It might have discarded older snapshots to reclaim space.

Have you rebooted into recovery and verified that there are no backups present?

 

[madrich]

[doublepost=1566768333][/doublepost]Unfortunately, one needs the Time Machine backup to restore to Mojave.

You should be able to restore to the Mojave or the original OSX your computer came installed with originally via iCloud. I think you need to hold Command+ R shift option buttons when you restart to get the menu from Apple.

https://support.apple.com/en-us/HT204904