ProSeries is pretty much useless until mid-December. 

And I wouldn't recommend transferring files until January (unless you plan to delete the originally transferred file and then re-transfer it again in January).

So you will need to be patient.

Most of mine Orgs transferred fine(as fine as possible) but at least one is giving the same error.

I don't know why either.

I have hundreds of files that were fine.  I do a lot of proforma things before the end of the year, and have been transferring files in November for over a decade of using PS.  I have never gotten this issue before.

I just got several errors with partnership files, then I deleted them.  I think there is a software issue that Intuit needs to address.  Releasing software that is typically marginally useful in November is pointless if they don't address it very soon.  Many accountants get the software and do what I am doing so that January can hit the ground running.  Imagine running into this in January....not being able to transfer files.

"Releasing software that is typically marginally useful in November is pointless"

True. That's why most of us decline to be the beta testers and wait for another update or 2 or 3 before we try to do anything other than have a look/see.