For those having morphology issues, check your browser console to see what the actual error is being returned. You should be receiving 200 back and everything is ok, however if you get 403 which I got when testing the error and you most likely will if it can't reach Yoast, then you will get the morph error.
As stated by Yoast here:
For Premium, we need to load morphology data from MyYoast. For this, we need to add functionality that loads a JSON file from a URL. This request should return the a 200 with the JSON file when it succeeds and a 403 with an error message in case it fails
You can actually remove that morph error message and put in something you want to read instead, although without looking at it further and not actually wanting to as well, it will knock out two options from Yoast.
With error message, all options at bottom and right.
With no error message. few options now missing at bottom and right
Anyways, if you can install using the existing files of which I can do after a clean cache and clean install then you are good and don't have to worry. However, if you still have issues then try this version here as it should work for you.
Plus yes, it does work with SEO....
@Kao X3
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