Update a closed Dynamics CRM Opportunity? Impossible! Yet you can.

Everyone knows that you can’t update a closed record within Dynamics CRM, right?  I mean, everyone knows that.

But what if it was not true?

I ran into a very strange situation last Friday where I was actually able to update a closed Opportunity programmatically – without first reopening it.

This was on a Dynamics CRM 2015 on-premises system and I verified it with Dynamics CRM 2016 Online using an Opportunity that was both closed as Won and Lost.

I am not sure if this is a feature or a bug or if you can do it on any other entities, but at least for Opportunities, that is currently the case.

If anyone else has time to test this process on any other entity, I’d love to know the results.