I've had a number of problems in getting X3 Producer to work with projects that had been started with 8.5.3 PE because its sorcerer's apprentice changes and eliminates things.
 
Like I'll open a project and get no sound or it's frozen and after a bit of troubleshooting find out that it had changed the external insert assignments for the 2 bus compressor to "none"
 
But on one project, all the fx and automation had been removed and all the pans were re-asigned to center. Every version of the project. I thought maybe if I opened it in 8.5.3 they'd be back but no dice.
 
Many hours of painstaking work, destroyed. WTF?

Did you save the projects in X3 and then tried to open them in 8.5.3?

You should try opening the projects in safe mode.

I assume you have a copy of 8.5.3 and backups of your work?

I tend to finish projects in the same version of Sonar that I started with. That generally avoids problems. If I upgrade Sonar I always backup projects first (in fact I always backup to an external drive at the end of the day, it's just common sense). During the day I back up projects under different filenames although I could have used auto save.

I'm sorry you lost your work.

John
Did you save the projects in X3 and then tried to open them in 8.5.3?

No. Why would I want to save the destruction?

CakeAlexS
You should try opening the projects in safe mode.

Will that bring back the missing stuff?

I assume you have a copy of 8.5.3 and backups of your work?

 
As I just said, "I thought maybe if I opened it in 8.5.3 they'd be back but no dice."
Backups are destroyed upon opening. several versions on two separate external hard drives.
 

I tend to finish projects in the same version of Sonar that I started with. That generally avoids problems.

I wasn't warned about that. I thought if I didn't have problems going from 6 PE to 7 PE to 8.5.3 PE why would X# **** things up?

 If I upgrade Sonar I always backup projects first (in fact I always backup to an external drive at the end of the day, it's just common sense). During the day I back up projects under different filenames although I could have used auto save..

That's exactly what I did. I have several different versions on 2 separate external hard drives and they are all ****ed.

I'm sorry you lost your work.

Do I get a refund? Is there a class action lawsuit I should know about?

Did you also move from a 32-bit 8.5.3 to a 64-bit X3?  
 
Any hardware changes from 8.5.3 to X3?
 
32-bit plugins in the 8.5.3 projects that maybe are not present in X3?
 
Bob Bone
 

No, no and probably.

Wait - you had some sort of project data loss, and then kept opening all of your backup copies until you had no more saved versions of your projects?
 
Bob Bone
 
 

I am just trying to figure out what happened, to try to help.
 
The additional backup versions, you opened them in 8.5.3 after trying to open them in X3, or did you only open those copies in 8.5.3 and find them messed up?  Just trying to understand.
 
Bob bone
 
 

The last one I opened with 8.5.3 PE 64 bit. I might have one more. I could try opening it in safe mode.
Anyway, I gotta chill. I'm riding my bike to the library -- I'll check back in a bit.