This is usually a decompression error.
While the SOLUS Ultra is an older platform, the 21.4 software brought several enhancements from Snap-on's more modern "Intelligent Diagnostics" ecosystem: Expanded Component Testing snapon solus ultra 214 update top
: Added a "No Communication" message on-screen to assist with connection troubleshooting. How to Perform the Update This is usually a decompression error