Traceback in logs of Cisco Router

[ArsenLiliyev]

Hie everyone.

There is a Cisco 2901 series router working by VPN tunnel and it working properly about 1 year after configurating. Now it gives a strange logs, which don't even drop in our syslog server. Logs like this: 

Feb 26 10:28:40.269: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:28:50.269: -Traceback= 36D3CC14z 36CC9A64z 30032B5Cz 30032B40z
Feb 26 10:28:50.273: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:28:59.693: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:29:00.385: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:29:01.941: -Traceback= 36D3CC14z 36CC9A64z 30032B5Cz 30032B40z
Feb 26 10:29:10.357: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:29:20.357: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:29:20.357: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:29:30.357: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:29:40.357: -Traceback= 36D3CC14z 36CC9A64z 30032B5Cz 30032B40z
Feb 26 10:29:40.357: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:29:40.361: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:29:50.357: -Traceback= 36D3CC14z 36CC9A64z 30032B5Cz 30032B40z
Feb 26 10:29:50.357: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:30:00.469: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
Feb 26 10:30:00.469: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z

As you can see, it gives it continuously and constantly. Can anybody explain where is there could be problem, and what does that logs mean? We have about 50 routers like this one, and in this long years nobody faced thing like this. 

[marce1000]

      >...Feb 26 10:28:40.269: -Traceback= 36D3CC14z 36D65434z 36D65514z 36D467B8z 36D58894z 36D58D2Cz 36D58DE4z 36D49C98z 36D4D7C8z 30032B5Cz 30032B40z
  - That is a bug or related to bugs  , it might have impact or not : best is to look at https://software.cisco.com/download/home/282774223/type/280805680/release/15.7.3M8
                            and upgrade to this latest advisory , if applicable

  The argument , it worked before is usually not valid ; because (new) bugs can also be 'discovered' by new application patterns and or network load , 

 M.

[ArsenLiliyev]

I checked, it is c2900-universalk9-mz.SPA.156-3.M8.bin right now on router. Then I download recommended version and check if log happens again with new soft. Thanks for advice!