Learning Forum

[Chris_g]

Hi everyone,

I am experiencing a weird issue in fluent, were I get the "error 126" after having an error during compiling from another UDF. So basically I compile a UDF, get a compiler error, fix the error, delete the libudf folder, compile again without any error, load the UDF and get the error 126. After that point it doesn't matter which UDF I compile (even very simple "Hello World" UDF) I will always get the error on loading. When I log out off and back into my account on the PC, the error is gone and the same UDFs as before compile and load fine up until I try to compile another UDF with an compiler error.

Do you have any idea on how to solve this problem?

I'm not sure if this is connected, but this problem only started recently after installing ANSYS Rocky (with fluent coupling).

Thanks for any help

Chris

[Chris_g]

One correction: It doesn't have to be a compilation error, other errors can trigger this as well. Today, my simulation threw a SIGSEGV error. After restarting fluent, on auto-compiling and loading the UDF I also got the error 126 but no compiler error.

[Rob]

What is the UDF hooked into?  Did you set the model up from scratch? I've seen a few issues when changing UDF.c files where the values the UDF needs to calculate the values used elsewhere didn't exist and caused a few errors. 

[Chris_g]

I did some further investigation, there is an error in my UDF that causes the SIGSEGV. This error then somehow seems to cause the error 126. I will probably find the error in the UDF after some more searching, but my problem is the 126 error as it makes debugging very tedious, because I have to close all programms and log off and back on my PC before trying something else.

I think the error 126 is somehow caused by the Rocky installation. I have not seen it before that and I tried on several PCs. 2 have Rocky installed and throw this error. One doesn't have a Rocky installation and also don't produce this error. Is there something modified by the Rocky installation that causes this behaviour?

[Rob]

If a UDF causes Fluent to fail you should just need to restart Fluent. Rocky does change a few things, but nothing that conflicts with standalone Fluent or the Clang compiler in Fluent. You are using the built in compiler?