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It could be Windows Defender killing it if that is the case. Make sure you have all folders and ".exe"s related to PSO2 and the Tweaker added to Defender's exclusions as I recall it is still "active"...

By doesn't work, do you mean it won't start, or something else?
If it's not starting, check the Task Manager and see if it is in your processes list; it could just be that it isn't starting...