I may not have the full picture, but erroring on missing version seems like a pretty good safeguard to have in place, so we don't run the risk of injecting incorrect versions if there is something wrong with the version file.

Could we maybe manually add the new plugin's version the first time instead?

I may not have the full picture, but erroring on missing version seems like a pretty good safeguard to have in place, so we don't run the risk of injecting incorrect versions if there is something wrong with the version file.

Could we maybe manually add the new plugin's version the first time instead?

Good point, however I think it will be quite easy to miss adding the version file and understanding where to add it for someone who's not familiar with the Website code.
I'm assuming we'll always have a v1.0.0 of a plugin so even if something is wrong with the version files it will still point to an existing plugin.

Maybe we can detect it's a new plugin somehow

OK so I think https://github.com/cloudquery/cloudquery/pull/5170/files#diff-02a351de4c8e66a0c9e62bd22b54e65e3ff7133ab407a20b8b82f006bb22feaeR27 should work for both cases (throwing an error when we need to, and allowing new plugins)