GNURadio MPM major compat number mismatch after update SDR to UHD 4.6

Hello,

I am using an Ettus N320 that I recently updated to UHD 4.6. However, now when I try and use GNURadio I get an error:

"RuntimeError: RuntimeError: MPM major compat number mismatch. Expected: 4.2 Actual: 5.3. Please update the version of MPM on your USRP device."

I'm guessing I need to update my GNURadio install somehow. I tried uninstalling and reinstalling, and reinstalled UHD4.6 from source, but still getting this error. Any suggestions on how to fix it? 

Thanks,

Steve