Seeing the error below when disabling a field?
If you see this error, it means the output you are trying to disable has been is mapped to a column in your Export destination. If you disable it, the destination will no longer receive the data for this field and the Export will fail.
If you still want to disable the field but want to ensure your export still works correctly, go to the Export blocks mentioned on the troubleshoot dialogue, and check the mapping for all the columns.