When previewing a transaction with multiple adjustments all the transaction need to belong to the same subscription.
You are attempting to preview a transaction with several adjustments, but the transactions associated to them have different subscription IDs
One or more transactions provided belong to different subscriptions. Transaction %s belongs to subscription %s, but transaction %s belongs to subscription %s
There are multiple adjustments for different transactions being previewed but some of them don't belong to the same subscription.
Check that all the transactions in the list of adjustments have the same subscription ID and remove the ones that don't match.