MPM Error Mismatch on the USRP X420 Using Linux OS

Issue Details

I am getting MPM error mismatch when trying to detect USRP in Linux OS: 

MPM major compact number mismatch. Expected 5.3 Actual 6.1. Please update the version of MPM on your USRP device.

Upgrading the UHD to v4.10 and updating mender to v4.10, helps detecting X420 using uhd_usrp_probe. However, GNU v3.10 still gives the same error, even if I keep the installation order (installing GNU Radio after UHD installation). 

Solution

The USRP X420 is running the MPM 6.1, and the UHD tools like uhd_usrp_probe works, but there is still an issue with the higher-level framework (GNU Radio) which is most probably linking to older UHD runtimes. 

For fixing this issue, the most recommended way is to uninstall the UHD and build it from scratch, then install the GNU Radio. You can find the full instruction in the following link: Building and Installing the USRP Open-Source Toolchain (UHD and GNU Radio) on Linux - Ettus Knowledge Base. 

Important note: Since Volk is no longer considered as a submodule of GNU Radio you must first install Volk and then install GNU Radio. You can find all details here.