Steps that will lead to this error in 11.17.2 and prior:

1.Borrow a license from license file A (Borrowed a license f4 from a pool of 6 licenses)

2.Use license file B or make changes in license file A and start the server(has 3 licenses)

3.Return the license that was borrowed in the first step(f4)

This error encountered above is a bug as ideally the license should get returned without any issues.

On a server restart, the borrow caches gets deleted (irrespective of the use case) and the contents of borrow cache is taken into the local buffer.

The same has been fixed in 11.18 Release , provided that the variable ls_allow_updated_feature_borrow should be set to 1 in lsvendor.c file.

New vendor variable "ls_allow_updated_feature_borrow" has been added to activate the validation for the server borrow cache entries, even if the code/SIGN value does not match with the newly loaded license files feature on restart of the server.