Argument 2 passed to _search_api_views_add_handlers() must be an array

Thanks for reporting!
Please test whether the attached patch resolves the issue.

After applying these various patches, the site failed to load. I executed it via CLI, and it just hung, so I went in and commented out everything within the function search_api_multi_views_data(). The site then loaded, so I went back and uncommented the function - the site still loaded as expected.

Next, I went in and added a view related to this module - everything worked fine, until I tried to save the view. The site again wouldn't load until I commented out the function again. After it loaded, I uncommented the lines and created another view.

It seems that there is an infinite loop here somewhere that is called only on a save operation. What's strange is that I can create a view no problem, and see that view's page without issue - indeed, searching the view as well as facets work fine - it's just during the save operation or the initial site load after enabling the module that it blows up.

What „various patches“? And does it work normally when using the unpatched module(s)?

If so, please try to find out which patch causes the problem and report there.

Let's discuss both issues in #1608356: Adapt Views integration to recent Search API changes.