I actually updated from 1.9.5 so yeah, it's weird that it shows an error related to 1.9.1.
I did as you say and deleted Playmaker folder entirely, then re-installed from package manager and run install from Playmaker window. I get this error at the end:
Unable to update following assemblies:Assets/PlayMaker/Editor/PlayMakerEditor.dll (Name = PlayMakerEditor, Error = 131) (Output: /var/folders/w5/y4l8442j1gd4sdk967p3lws00000gn/T/tmp4e247c90.tmp)
[AssemblyUpdater] Failed to resolve assembly System.CodeDom, Version=4.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51. SearchPaths: Assets/PlayMaker/Editor, /Applications/Unity/Hub/Editor/2022.3.3f1/Unity.app/Contents/NetStandard/ref/2.1.0, /Applications/Unity/Hub/Editor/2022.3.3f1/Unity.app/Contents/NetStandard/compat/2.1.0/shims/netstandard
I ignore it and then put back the Resources folder with the globals.
I unfortunately get the exact same NullReferenceExceptions again when I hit play in the editor.
I also tried to uninstall the Playmaker Utils (deleted the folder) and re-installed from the ecosystem, yet same issue remains.