Having downloaded a package from Trados Enterprise / Trados Studio - Cloud Capabilities / Trados Team that contains termbase data, and opened it in Trados Studio 2019, you realise that the project has no termbase. Looking at Project Settings confirms this:

 

Solution: Upgrade to Trados Studio 2021 or Trados Studio 2022

Trados Studio 2021 and above have full Trados Enterprise / Trados Studio - Cloud Capabilities / Trados Team package compatibility.
 

Workaround: Use Online Editor

If you have purchased the Online Editor option, the file can be worked on there with full termbase functionality.
 

Workaround: Use "Open in Studio" Option

If you open the project directly in Studio you will have access to the termbase. However this relies on an active, stable internet connection.
 

Workaround: Create a Termbase and Attach it to the Project

1. Download the package and open it in Studio as usual.
    
2. Open File Explorer and browse to the location you downloaded the package.
    
3. Click View and make sure the box next to File name extensions is ticked.
   
   
    
4. Click on the package, and then right-click it. Choose Rename.
   
   
    
5. Add .zip to the end of the filename and then press Enter.
   
   
    
6. Choose Yes when asked if you are sure you want to change the filename extension.
   
   
    
7. Right-click the renamed file and choose Extract All...
   
   
    
8. Untick the box next to Show extracted files when complete and then click Extract.
   
   
    
9. Create a termbase using the termbase definition and export file found in the LcTermbases subfolder of the location you extracted the package to in step 8.
    
10. Add the termbase to the project in Studio.

Trados Studio 2019 and below does not support this feature.