I have sonar X1 Producer Expanded and Sonar 6, using EWQL samples.
 
When I open projects that use samples that have since been moved to another path (another drive), I get "samples missing" prompts asking me where they are.
 
That message isn't from Sonar, is it? It's from PLAY?

SONAR does not know anything about samples. SONAR will display a "Find Missing Audio" dialog when the audio clips in a track cannot be found. You can test if Play is issuing the message by starting the project in safe mode (hold the SHIFT key while opening the project) and do not load Play when prompted to load plug-ins.

Samples not found messages would be issued from one or more sample-based plugins that are expecting a given preset's samples to be in the listed location, but are not found there.
 
So, if you are using something like Kontakt and see those kinds of messages, it means that the sample files for a preset used in a Kontakt instance in this project are no longer where they were when the project was saved.  Kontakt offers you ways to locate the missing files, so as long as you can find them, or let it search generically for them, you should be OK, but once you DO find them, you are going to want to rebuild the Kontakt database, and maybe also resave the repaired instrument, OR move the sample back to where Kontakt was expecting them.
 
The above will vary from product to product, but the idea is the same.
 
Bob Bone
 

Ok, thanks guys. So I guess I'm seeing PLAY push a notification through a Sonar dialog box, which had me a bit confused. Holding down shift helped prove that I guess.
 
Thanks, that makes sense.