I am an experienced Revit user.
In one of my models, I am getting the "no auto route soltuon found error" all of the sudden for no apparent reason.
I was working in it yesterday with no problems. When I opened it up today and tried to draw ductwork, I got this error.
I get this error when I do ANYTHING with ductwork. If I try and connect to existing, modify existing (just shorten or lengthen), try and draw a new piece off in space, etc...
My model as of right now is completely useless and I have no idea how to fix this error.
I tried auditing the model and that didn't fix it.
In addition, in my other models, I have no problems whatsoever drawing ductwork, connecting, modifying, etc...
That is a head scratcher.
Usually that error (and I'm sure your aware) is from undefined fittings in the duct type or lack of necessary space to place a fitting.
You mentioned just drawing a straight segment of duct gives you this error?... Perhaps there is an issue with the Duct Profile CSV file specific to this project.
The strange thing is any file location settings within revit aren't per project, but rather global, especially if it is working in a new project or another existing.
Do you have your journal files? <located here-->C:\Users\yourname\AppData\Local\Autodesk\Revit\Aut
Open a new project and drag and drop a previous journal file to see where it broke. There is a software called baretail that makes it easier to go through the journal as a step by step macro interface.
If there is nothing you can do, I would send Adesk the file
(if your on subscription) and let them figure it out.