Non-optional inputs from the following input groups and their slots are not connected: particles.alignments3D

I’m trying to import a particle stack from relion 3 into cs 2.15. Importing didn’t work until I manually removed the the block above loop_ in my star file, otherwise I got this:

[CPU: 284.2 MB] Traceback (most recent call last):
File “cryosparc2_master/cryosparc2_compute/run.py”, line 85, in cryosparc2_compute.run.main
File “cryosparc2_compute/jobs/imports/run.py”, line 255, in run_import_particles
assert do_blob or do_ctf or do_location or do_pose, "Could not import star file: too many fields missing. "
AssertionError: Could not import star file: too many fields missing.

Now after removing the aforementioned block, the import worked fine, but when I tried to run local refinement, I got the following: [CPU: 99.2 MB] Traceback (most recent call last):
File “cryosparc2_worker/cryosparc2_compute/run.py”, line 52, in cryosparc2_compute.run.main
File “cryosparc2_compute/jobs/runcommon.py”, line 823, in check_default_inputs
assert False, 'Non-optional inputs from the following input groups and their slots are not connected: ’ + missing_inputs + ‘. Please connect all required inputs.’
AssertionError: Non-optional inputs from the following input groups and their slots are not connected: particles.alignments3D. Please connect all required inputs.

which could only mean, my import did not work correctly! what is the proper way to import my particles given the two versions of relion and cs highlighted above?