if using the BP views, it is more than likely that the Contact Company is not in view.
Just like on the Incident, there is the concept of a Requester and a Contact person. Sounds like you are having an issue with the value being populated for the Contact persons Company.
How did you create the Problem request, was it created from an Incident or a new request?
You may need to look at the Contact information and re-select the Company. Alternately you would need to log the Active Links as Laurent has mentioned to see what values are being populated and are failing the drop-down menu values for the field in question. The Contact Company field will have a menu attached, so you would need to validate that the value is indeed in the menu for this field.
From the Filters, this is what is being set:
--> Passed -- perform actions
> 0: Set Fields
> Requestor ID (1000000337) = superuser
> Contact Company (1000000082) = ePlus
> Person ID (1000000080) = PPL000000003883
> Site ID (1000000074) = STE000000003746
> Phone Number Business (1000000056) = ###
> Corporate ID (1000000054) =
> Middle Initial (1000000020) =
> First Name (1000000019) = superuser
> Last Name (1000000018) = superuser
> Company (1000000001) = ePlus
> z1D_Problem_Location (303915300) = ePlus Pottstown
> Site (260000001) = ePlus Pottstown
> Region (200000012) =
> Site Group (200000007) =
I would start by validating the menu attached to this field contains the value being set above.