Upgrade path not available

[RahmaSallm]

Hi,

We have a CISCO1921/K9 with IOS file c1900-universalk9-mz.SPA.152-3.T.bin
We want to upgrade to c1900-universalk9-mz.SPA.157-3.M8.bin, latest release by cisco.

I checked the release notes but the link for the 1900 series routers isn't working. 

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/15-7m/release/notes/15-7-3-m-rel-notes.html#con_1025382

Could I find this information somewhere else?

[balaji.bandi]

Page not show because may be due to end of Life.  ( i see all the end of life links broken)

https://www.cisco.com/c/en/us/products/routers/1921-integrated-services-router-isr/index.html

I do not see any issue you can upgrade from 152 to 157.  ( Hope you have latest ROMMON code  15.0(1r)M9)

Follow below guide should work as expected :

https://www.cisco.com/c/en/us/support/docs/routers/3800-series-integrated-services-routers/49044-sw-upgrade-proc-ram.html