Too few frames after grouping (1<3) for 2 frame movies

[andreanans]

We're getting the following error in relion-5.0.0-commit-d24f65

The tomography movies contain 2 frames each, but when we try to motion-correct them using Relion's implementation, we get the following error (group frames set to 1):

Skipped movie Movies/Position_1_3_041_etc_Fractions.mrc: too few frames after (2<3) after grouping
Probably the movie is truncated or you made a mistake in frame grouping

We get a similar error if we set group frames to 2

Skipped movie Movies/Position_1_3_041_etc_Fractions.mrc: too few frames after (1<3) after grouping

Do tomography movies need to have at least 3 frames?