Okay, I 'll try, thanks
Hello, @Shimwell it’s the same issue as before, and I haven’t found a satisfactory solution yet. I am feeling distressed now. I’ve been using the same example you provided, but the problem mentioned above keeps occurring.
The only thing I can think of is to use the ENDF b8.0 based chain file instead of the ENDF b7.1. Did the pip install instructions work for you? If not here is a download link https://raw.githubusercontent.com/openmc-data-storage/openmc_data/main/src/openmc_data/depletion/chain_endf_b8.0.xml
Thank you for the link, I succeeded 