After hitting SC, the tree profiles start to get read in the background but the process never ends as it gets stuck before the profiles are displayed, hence none of the profiles can be even compared to the existing ones nor can they be copied... This doesn't happen very frequently but just enough to be an annoyance.
Example: copying this profile's family https://www.ancestry.com/family-tree/person/tree/173049710/person/222268629241/facts to this profile: https://www.geni.com/people/Sarolta-Skavrian-Skovran/6000000180154899995
Error screenshot (V4.11.3.1):

@pquenee Same thing happens with V4.11.3.935 fork but with a somewhat different error:
