How do I remove a field from being mapped to Salesforce?

[Anonymous]

I have hidden these fields but I got an error last evening that states "Salesforce Sync Error: Required Field for Salesforce Sync is Not Visible." This field is not required in Salesforce and has never been. We no longer use it and I've deleted it out of Salesforce, but as you all know, you can't delete fields out of Marketo, you must hide them. 

[Anonymous]

Yes, you are correct. you will not be able to delete the field. Choose same field in marketo and try to block field update from SFDC for this specific field which you deleted from SFDC.

[Anonymous]

It is blocked. Thanks