LAPACK: Routine ZPOTRF failed!
Occurred during hybrid calculations, try switching between well-converged WAVECARS and CHGCARs. I believe preconverging with PBE to 1e-8 may have fixed it. Custodian halves the potim and deletes chgcar and wavecar. Perhaps lowering the TIME stap may improve stability based on this. I think they may also turn off symmetry but I'd try everything else first if you're doing HSE... I got past it without doing so.