What’s problem with this?
openfhe-development-main/src/core/include/lattice/hal/default/dcrtpoly-impl.h:l.698:DropLastElement(): DropLastElement: Removing last element of DCRTPoly renders it invalid.
You are trying to call modreduce or run a computation beyond the currently set multiplicative depth. Increasing the multiplicative depth should help. Note that we typically do not answer questions where minimal working examples are not provided.