Check out their github and see if someone already had such issue and received an answer from the authors. Otherwise, you can report the issue (in github also)..

Yesterday I used this notebook and it worked fine.

The Alphafold tool is a deep learning-based protein folding prediction tool, and it typically outputs a predicted 3D structure in PDB format. If you are not getting the output in PDB format, there could be several reasons for this:

If you have tried these steps and you are still not getting the output in PDB format, you may want to contact the Alphafold support team for further assistance. They may be able to provide additional information or help you troubleshoot the issue.

I have just finished some predictions in this notebook.. It works fine. Just read careful where you can find the results after it finishes.

I had a similar issue. Are you getting PDF files as well? Because Adobe is one of the main programs on my computer and I could find out that the .pdb files were considered to be a PDF and opened with it. But when you choose to open with Chimera it works.