# Problem with fftw\_loadwisom() crashing example

**URL:** <https://discourse.channelflow.ch/t/problem-with-fftw-loadwisom-crashing-example/53>\
**Category:** Miscellaneous\
**Created:** [February 12, 2019, 11:56am UTC](https://discourse.channelflow.ch/t/problem-with-fftw-loadwisom-crashing-example/53 "2019-02-12T11:56:27Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Crunch2018](https://avatars.discourse-cdn.com/v4/letter/c/34f0e0/32.png) [@Crunch2018](https://discourse.channelflow.ch/u/Crunch2018)\
**Post date:** [February 12, 2019, 11:56am UTC](https://discourse.channelflow.ch/t/problem-with-fftw-loadwisom-crashing-example/53/1 "2019-02-12T11:56:27Z")

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Hello everyone,

I am writing tot his forum as a friend of mine who has been helping me get the example couette script up and running found a problem with the fftw\_loadwisdom function. Commenting it out allows the program to run but leaving it in results in the following error :

terminate called after throwing an instance of ‘std::logic\_error’  
what(): basic\_string::\_M\_construct null not valid  
Aborted (core dumped)

We were not sure of the significance of this function and I am wondering is it just better to leave it out altogether? Also, is there an easy way to link the chflow library as I am currently linking all the cpp and h files by hand meaning it takes longer than it should to compile.

Thank you,

Best Regards,  
Conor