whereami requires a template space to be associated with the dataset. That may have gotten lost somehow. What does this command show?
3dinfo -space dset+tlrc
To force a space onto a dataset, you can apply one with
3drefit -space MyTemplateSpace dset+tlrc
Replace "MyTemplateSpace" with the name of the space of your template (MNI, TT_N27, TLRC,...).