Communication with RekordoxAgent Failed and switching to new PC

I’ll try to make this story short and try to give as many details as possible and I might also forget some info but I’ll try my best. I want to apologize already for the long read.

I bought the DDJ-400 around 2021 and I downloaded rekordbox back then. I think the box of the controller had a code and I put on the code to activate my account and it is linked to an email.

Fast forward to about a few months ago, the computer I was using started to work pretty badly so one of my friends gifted me his computer which was a massive upgrade. I downloaded rekordbox to this new computer and I selected the free plan as I never paid a penny in rekordbox apart from the controller itself. When I connected the cable from the new computer to the DDJ-400, nothing worked and it had a message that was probably saying that I was on a 30 day free trial. The email of the account on the new computer I think is the same so I thought it was weird it wasn’t working but I forgot about it for a while and in my old computer everything worked nicely still so I kept using it.

In the meantime I tried to put as many songs possible from rekordbox to a pen so I can use it on the new computer.

Eventually I opened rekordbox on new computer with the pen and everything worked perfectly, probably due to the fact the 30 days were done, and just a few songs weren’t loading and I thought it was because of the pen. So I went back to my old computer to put the songs on my pen to make sure I got everything and there wouldn’t be any more problems loading songs.

And then I get hit with the “Communication with RekordboxAgent failed” error and I can’t open rekordbox on my old computer. And not only that on my new computer the library is empty which I still think is weird since the account is the same so why not have the songs in there too? So I can use rekordbox on my new computer with the pen but with some songs not loading, I’d like to go back to my old computer to make sure I get everything on to the pen.

So my questions are 1. How do I fix the error on my old computer, so that I can access the library there, put the songs on the pen and then put the songs from the pen into the new computer? and 2. In case I can’t fix the old computer and considering that it’s supposedly the same account, how can I somehow get the library that I had on the old computer into the new computer by doing some sort of link through accounts.

Sorry if the post is too long and I appreciate if someone could help me. Thank you for reading.