Can we get on a call to discuss this? Please send your availability to my email firstname.lastname@example.org
As suggested in the support case instead of creating field from "Update Field Value" trigger you could be using the following solution:
Create a related field in "Crane Object" by selecting the related object as "Summary Information" with related field "Amount of records".
This will resolve the problem.
Meanwhile we will investigate further to analyse the root cause for the error.