Dear Nektar community, After I installed Nektar4.4.1 in my Ubuntu (18.04) by source code, I successfully run the two examples (1D Advection equ and 2D Helmholtz problem) in User guide, Chapter 6. But when I tried the third example (AdvectionDiffusion.xml, in 6.4.3 Advection dominated mass transport in a pipe), I bumped into a segmentation error. I am a newbie in Nektar, So I could not find which one is a problem in the input xml file. Could you give me an idea to solve the problem? I really want to learn Nektar. Thank you. Dongmyung Suh ---------------------------------------------------------------------------------------------------------------- T5500:~/Desktop/Nektar_exercise/AdvectionDiffusion$ ADRSolver AdvectionDiffusion.xml Warning: Level 0 assertion violation Using Default variable expansion definition for field: u [T5500:03146] *** Process received signal *** [T5500:03146] *Signal: Segmentation fault (11)* [T5500:03146] Signal code: Address not mapped (1) [T5500:03146] Failing at address: 0x8 [T5500:03146] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x3ef20)[0x7fbe5b148f20] [T5500:03146] [ 1] /home/dongmyung/Software/nektar++-4.4.1/build/dist/lib64/nektar++-4.4.1/libSolverUtils.so.4.4.1(_ZN6Nektar11SolverUtils14UnsteadySystem17v_GenerateSummaryERSt6vectorISt4pairINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES9_ESaISA_EE+0x28f)[0x7fbe5e33f9af] [T5500:03146] [ 2] /home/dongmyung/Software/nektar++-4.4.1/build/dist/lib64/nektar++-4.4.1/libSolverUtils.so.4.4.1(_ZN6Nektar11SolverUtils14DriverStandard9v_ExecuteERSo+0x4a4)[0x7fbe5e2e3b14] [T5500:03146] [ 3] ADRSolver(main+0x177)[0x55d5de973037] [T5500:03146] [ 4] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xe7)[0x7fbe5b12bb97] [T5500:03146] [ 5] ADRSolver(_start+0x2a)[0x55d5de98329a] [T5500:03146] *** End of error message *** Segmentation fault (core dumped) ---------------------------------------------------------------------------------------------------------------------