[How to Change Material 1 from PLA (Generic) to Unknown?]

Now, I am getting a message:"Difference between detected height of both PrintCores exceeds realistic values. I tried active, and manually leveling of the table without any success. 

[How to Change Material 1 from PLA (Generic) to Unknown?]

You were right on.  I took the PVA spool off, and now I can select the material. I have the Ultimaker 3. Yes, I have a material station. Thanks.

[How to Change Material 1 from PLA (Generic) to Unknown?]

I am trying to load PLA Silver. Ultimaker is displaying PVA is not compatible with the AA 0.4 Printcore.

I continue, and Material Type appears. It said material not detected. I try to select material, but it changes back to displaying PVA is not compatible with the AA 0.4 Printcore, before I can select PLA.