I am currently working on a migrated 2019 farm. The migration took place in 2010-> 2013-> 2016-> 2019 in one go.
Now I find the old one
CoreResultsWebPart No results are displayed at all. The search works fine and if I remove the
CoreResultsWebPart and replace it with the new one
ResultScriptWebPart Results are displayed.
Is it possible that the old ones
CoreResultsWebPart does 2019 not work at all?