I have a lot of older projects (just the rough tracks) that don't have any Fx added and would like to use the Pro Channel before mxing them down. Are people having issues only when there are Fx used in 8.5 and then re-opening in X1?

Mesh, I have not had a problem opening any project from any version of Sonar in X1.

The only thing is plugins I no longer use or I have updated them to new versions. That will cause Sonar to ask and let me know that those plugins are no longer being loaded. This is not a problem. You can't expect X1 to load plugins that are not there or are 32 bit DX if like I am running the 64 bit version.

To be clear here I have the demo songs going all the way back to Sonar 1 for just this reason to check compatibility and so far not a single project has refused to open. All my projects that I have from 8.5.3 open find as well. Some of those were started in older versions.

If however you think a problem could happen then just to be very safe backup your project to a safe place before opening it.

X1 is backward compatible to all Sonar and Pro Audio projects. However an X1 project may not open in an earlier version of Sonar.

Cool Mesh. I want it clear I don't know why some seem to have problems opening projects in X1. I never have had a problem.