Problem Netgen/NGSolve does not start, no error; any tips?

Dear Community,

i tried to (re)install Netgen/NGSolve on my Windows 10 PC as described in the Download section. Not the first time on this machine. Why the reinstall? Well, it stopped working, without any strange behaviour. I didn't used the program for weeks and when i tried, it stopped at the following point:

This happens also after a new installation. I de- and reinstalled Python (3.7.9), Microsoft Visual Studio 2017 Redistributables. Tried different older versions (of Netgen/NGSolve) with the same outcome.
On a different W10-PC it worked (with the same installation files) like a charme.

Can you help me or give me a hint what i can try?

Hi Peter,

what does happen if you import ngsolve from python?
python3
>> import ngsolve

Another try: In the command line, navigate to the netgen bin directory (the one containing netgen.exe) and try to run it from there.

It might be that netgen loads an incompatible version of a .dll and dies without any error message. We had troubles like this when another software provides tcl.dll and the path to the other .dll comes before the netgen directory in the PATH environment variable.

Best,
Matthias

Hi Matthias,

thank you for your response!

this happens, when i import ngsolve:

so, no error message, but also nothing more.

starting netgen (with command line) at the bin directory leads to the same result described in the first post.

I compared the PATH enviroment variables for both W10-PCs. They seem to be the same, on the one with the problem there are a few more entries (Matlab, CMake, TDM-GCC, Miktex, Git).

Is there a way to find the incompatible dll or perhaps do you know another workaround?

Best, Peter

Miktex does ring a bell, maybe that's the issue.

You can check the loaded dlls (and the symbols) with the dependency walker:
dependencywalker.com/
Just load the netgen.exe and see if you get any errors/red library names (don't worry about the ms-api-.... stuff, that's usual).

Best,
Matthias

Hi Matthias, hi all,

I haven't it figured out yet. I removed Miktex and reinstalled netgen/ngsolve, but it stops at the same time.

dependency walker (as far as I can tell) gives no errors (except these EXT- and API-MS and a few false-positive) regarding ngsolve.

Best,
Peter

Guess guess i'll try a few more combinations this weekend

Have you tried removing the path variables that are different? Does it work then? Then you can try adding them one by one and see which causes the problem...

Best
Christopher