Error While Checking Disk Space

I moved your post to a better forum. From LrC to the proper Lr forum

I hope this helps and best of luck.

Nope. I'm not a real fan of Lightroom, I use it very little. I'm primarily a LrC user. Keep watching, someone might have a good idea.

Yes, what you indicate is confusing. If you are truly using Lightroom 3.3 then there are no backup catalogs. The catalog is in the cloud, and you don't have access to it to be able to back it up. Lightroom Classic creates local catalog backups, but Lightroom does not.

CATALINA

So some points on MACOS Catalina as it effects Adobe PS, LrC, and to some effect Lr.

First up, the older products, Adobe Photoshop Lightroom CC v6.14, fie example, use a 32bit install app. Catalina absolutely will not run 32bit apps. Period. So, if LR 6.14 exists pre Catalina, as in already installed, Ok. But if you need to install it post Catalina, no joy.

Moving on, increased Cyber Security in Catalina, specifically Applications need rights. Many Catalina users fail to answer an inquiry as to allowing an app to use file space with yes, and Catalina then refuses access. Fixable

Outside of any app. In the MACOS, bring up System Preferences, select Security and Privacy, select Privacy tab, scroll down to Files and Folders, For LrC and while you are at it, foe PS, make sure all drve types are checked (removablevolumns is often the issue). This should not be an issue with Lr. If you store catalogs or photos in the sys folder Photos, scroll up and deal with that right, add LrC. For some reason, some users are told to scroll to Full Disk Access and add LrC (I do not see that issue in my rig, LrC is not included)

see: https://nektony.com/duplicate-finder-free/folders-permission

Some confusion. You are stating a Adobe Plan, so a subscription, you are stating LR v3.3. Your stating a 1TB plan. So, first impression is not Lightroom Classic, but Lightroom Desktop a.k.a LR Cloudy. or just Lightroom. So one would think the Lightroom Plan.  Lightroom with 1 TB cloud storage.

BUT, you also talk of Catalog (as in Lightroom Classic) and Photoshop. So, then one may think the Adobe Photography Plan with the 1TB option.

Current versions are

Lightroom (Lr) v3.3

Lightroom Classic (LrC) v9.3

Both are 64bit apps, neither uses a 32bit installer (like Lightrrom v6.14 ir older). Both work with MACOS Catalina, and Windows 10.

Lightroom stores photos on the cloud, and it uses Albums (stored in the cloud)

Lightroom Classic stores photos on a locol hard drive or NAS, it uses Catalogs (on local hard drive, never ever on NAS)