This typically happens when you install a new version of DeePMD-kit and copy directly the generated USER-DEEPMD
to a LAMMPS source code folder and re-install LAMMPS.
To solve this problem, it suffices to first remove USER-DEEPMD
from LAMMPS source code by
make no-user-deepmd
and then install the new USER-DEEPMD
.
If this does not solve your problem, try to decompress the LAMMPS source tarball and install LAMMPS from scratch again, which typically should be very fast.