Glitch Rendering Individual Audio Tracks

[RJWlaw@aol.com]

Last iteration of T6, 64-bit. Win7 64-bit 24gigRAM i7 CPU

On third project where this has happened. Each time on 3 or 4 tracks. Other tracks render fine.

Try to render individual audio track with unremarkable plugin.

T6 freezes "Not Responding."

Leave machine alone for 10 minutes. No change.

Force a shutdown of T6 and reboot.

Restart T6. Remove all plugins from track.

Try to render track. Same exact result. Reboot. Restart T6

Open new project. Copy and past clips from track into new project edit. Place plugins. Render individual track. Render works.

Go back to first project. Try to render individual track. T6 freezes "Not Responding."

Nothing unusual about clips on track where rendering is being attempted. Can be a lead guitar track spliced together from different takes or vocals comped.

Why do the copied clips placed into the new empty project edit render with the same plugins just fine and the same clips will not render even if plugins are removed in the original project?

What can be doing this?