# Latest MUMPS (ver 5.3.3) Users' Guide

 For those using the MUltifrontal Massively Parallel Solver (MUMPS), the users' guide for version 5.3.3 (June 15, 2020) can be found at:  http://mumps.enseeiht.fr/doc/userguide_5.3.3.pdfWhile FEATool may use an earlier version, the latest manual is still useful for decoding Warning/Error messages returned to FEATool.  The "Error diagnostics" chapter (8) begins on page 91.   Here is a message returned on one of my problems: Warning: MUMPS linear solver failed with error INFO(1:2) = -10:63787] From page 92 : --10 Numerically singular matrix. INFO(2) holds the number of eliminated pivots. In this case a numerically singular matrix was encountered and the number of eliminated pivots was 63787. Regards, -Randal