Compiler error or code error?

[PierU]

This part is not a problem:

@AN1M4DOS

ifort: remark #10448: Intel(R) Fortran Compiler Classic (ifort) is now deprecated and will be discontinued late 2024. Intel recommends that customers transition now to using the LLVM-based Intel(R) Fortran Compiler (ifx) for continued Windows* and Linux* support, new language support, new language features, and optimizations. Use ‘-diag-disable=10448’ to disable this message.

For the rest, it’s clearly a compiler bug.

Which version of ifort are you using? You may upgrade to the lastest ifx version and see if the bug is still present or not.

Or, you can try finding a workaround. You may progressively comment parts of the new code, until the error disappear. At least you will have an idea about which part of the code results in the internal compiler error.