Error message displayed is convert_post_SAC_CiscoMIB:Nvram block due to mismatch between configuration and CatOS or IOS version (such as, when installing a new version of code, or loading the configuration from another device). Usually, this is an informational message only and is of no concern.
These console messages are often generated when the following occurs:
upgrading or downgrading CatOS code versions
loading a switch configuration generated by another switch
using a switch configuration from another version of code
failover to the standby supervisor has occurred
Different versions of code contain variables that are stored in NVRAM. When the switch initially boots to a newer or older version of CatOS, it will convert the previous configuration to a version usable by the current boot image. During this process a particular memory block that is not needed or usable in it's current form will be de-allocated rather than converted. This internal function generates the error message.
The generation of this message is generally informational only.
Compare the previous configuration with the current configuration to verify that all previously configured software features were properly recognized and enabled.