This article will help you with troubleshooting an issue with downgrading the software version on PTP 450 product line radios from software version 20.x to 16.x via CNUT.
All PTP 450 product line radios only.
Error that will appear in CNUT: “Message: Invalid File Image”
In release 20.x onward, there is a flag called, BHS Tx Power Control, if it is enabled, radio cannot be downgraded to lower loads.
Therefore we must disable this flag under the Slave → Configuration → Radio → BHS Tx Power Control → Disabled as shown in the screenshot below:
After disabling this option, try downgrading the software version to 16.x version.
Note: This is only applicable to PTP 450 radios.