Symptoms

Under certain circumstances you may run into the problem where you unable to check in view due to the following exception on Save/Check-in operation:

Error 2601, Level 14, State 1, Procedure aDeploy Exception on View on Save operation Cannot insert duplicate key row in object

Exact error message may vary but you will notice that it always say "Exception on Save operation Cannot insert duplicate key row in object"
 

Diagnoses

This error may happen in K2 4.6.11 and earlier versions of K2 and usually recreation of affected view (if it is acceptable) resolves this problem.

Latest K2 smartforms update rollup for K2 4.6.11 available upon request from K2 support addresses number of issues with "Cannot insert duplicate key row error" error and should prevent this type of problem from all these fixes also included in 4.7 release.
 

Resolution

It is recommended to apply latest K2 smartforms update rollup for K2 4.6.11 to avoid similar errors in the future or upgrade to 4.7 which has these fixes included OOB.

In addition to this, K2 4.7 contains ALM functionality which is helpful for visibility of missing dependencies on a different levels to avoid issues similar to one described above.