sorry you are having so much trouble getting it to work.
Usually, the y_ea_normparams.nii file will be generated if you run an SPM-based normalization within Lead-DBS (DARTEL, Segment). However, I’d recommend to use Advanced Normalization Tools for now – it’s just much better tested because we use it ourselves. I’d still like to find out how the problem originated. Could you please do the following:
1. Run (only) Normalization again (DARTEL) and check if ea_normparams.nii really isn’t being generated and if so, if an error message appeared. Please always post full error messages (the whole red text in Matlab), otherwise, they are often useless for me.
2. If the file really doesn’t appear, try running the ANTs based normalization and see if things work from here.
If both doesn’t work, we should get in contact via mail and you’d need to somehow send me the dataset in an anonymized way so I could debug and see where the problem originated.