3D Warehouse not working for SU2015Pro

Hi all - been using SketchUp 2015 Pro since, well, 2015, but have run into a problem.
The majority of models in-app 3D Warehouse will no longer download, instead giving the error:
No download files are available

If I visit the wrehouse through a browser, I can download the same model but only have the option of 2018, 2018 or Collada File(?)
What’s happend? Is this some sort of enforced update?

This has been covered in other threads.

If I remember correctly, SU2015 can import the Collada file.

Thanks for the reply - I’m new to the forum today and yet to find my way around. Apologies for the doubled-up topic.

I didn’t see a doubled up topic. I just move it to the Warehouse category.

This seems not like a recent change, although the topic comes up recently very often (?).

Older versions could be made to fallback to import the Collada file in place of the unavailable skp 2015 file (but this would require updating unsupported versions, so this won’t benefit users before 2020+3).