Core Issue
The software has detected that the configuration saved in memory was written by a later version of the software. There might be commands saved in memory that are not implemented by the earlier software version.
Resolution
To resolve this issue, examine all the messages printed while the router was booting.
For each message about an unknown command, determine whether that feature is required. If any of the unknown command features is required, upgrade to a later version of software that supports the required feature.
For software upgrade information, refer to the document that applies to your platform:
- Cisco IOS Software Upgrade Procedure for Cisco 801, 802, 803, 804, and 805 Series Routers
- Upgrading Cisco IOS Software for the Cisco 806, 826, 827, 828, and SOHO70 Routers
- Software Upgrade Procedure for the 1000, 1400, 1600-R, 1700, 2600, 3600, 3700, 4000, 4500, 4700, AS5300, and the MC3810
- Software Installation and Upgrade Procedure for the 1600, 2000, 2500, 3000, AS5100, and AS5200
- Software Installation and Upgrade Procedures for the RP and RSP7000, 7100, 7200, 7300, 7400, 7500, 7600, 10000 (ESR), 12000, uBR71XX, uBR72XX, and uBR10000
- Upgrading IOS Software on Cisco AS5800 Access Servers
