Hi @AndriC,
‘Deal Sales 2022 Proposal Sent’ is a deal stage, I assume?
Is your property maybe used as a required field for the ‘Deal Sales 2022 Proposal Sent’ stage? Set up and manage object pipelines (scroll down to ‘To customize the deal properties presented to users when a deal moves to a specific stage’)
If the property is referenced there, you would have to remove it. You should then be able to archive the property.
Best regards!
