Heuristic3 Assertion failed?

[fffmath]

Hi, flatter is really fast, thank you very much for this job. It's great, but I encountered the following problem when dealing with the coppersmith lattice. When the parameter m is small, there is no problem, but when m is large, I encountered this. Is this also related to insufficient memory? If not, how can I avoid it. Note: I am using an upper triangular matrix.

flatter: /flatter/src/problems/lattice_reduction/heuristic_3.cpp:328: virtual void flatter::LatticeReductionImpl::Heuristic3::collect_U(): Assertion `mpz_cmp_ui(dU_iter(i,j), 0) == 0' failed.
Command '['flatter']' died with <Signals.SIGABRT: 6>.