Hi,
A recent email campaign resulted in half of the responses not being added to the SFDC campaign with the following Detail: Failed: {unable to obtain exclusive access to this record or 1 records: 7010O000001HGVwQAO}. Is anyone familiar with this error message? Any info would be appreciated. Thanks!
From my experience that results when someone is actively editing the record in SFDC. Or if you see it more often than not, your flow steps could be updating the record, and not have finished, which may also lead to that warning. If that's the case, you can try adding a wait step of a minute or two before adding to the campaign to let other processes complete -- or if it was from someone else in SFDC editing the record at the same time, sometimes you're out of luck and have to re-sync later.
It's also possible that there are a bunch of other processes running in SFDC at the same time. If your SFDC processes are complex/bloated, you can get these errors. Often the resolve themselves. If it's happening a lot, talk to your SFDC Admin/Dev about how to troubleshoot. There's not that much that you can do on the Marketo side.
You can check this thread for more details: Salesforce Sync Error: UNABLE_TO_LOCK_ROW