After Upgrading, multiple occurrences of files not able to be imported. Error: There was a problem while attempting to upload your document. Please contact your administrator. This is seemingly related to the keywords, as there is not a problem importing when keywords are not filled out. Will not work in Unity but seems to work in the thick client.
It was discovered that the impacted keyword was an auto-number keyword which are only supported during the creation of Unity forms/E-forms. Provided this information to the end user as well. This explains why creating a new numerical keyword did not display the same behavior; auto-number keywords cannot be manually added. The "Access Restricted Keywords" error/privilege were not pertinent to this process even though that's the error that was thrown.