Why am I receiving a "Failed to Apply Changes" error when confirming changes in the splitting view?

This error refers to an action that was unable to complete due to previous requests not being completed at the time. For example, a user might delete several splits and modify the document types for 100 documents in the original file. Once the user confirms their changes, Thomson Reuters Document Intelligence will begin to reprocess the documents to reflect the changes and reclassify and extract thoughts as needed. This process will apply to all of the documents in the original file and can take some time depending on the number of changes and documents involved. While this action is processing, any subsequent actions submitted will not go through and will result in the "Failed to Apply Changes" error notification in the red window in the bottom right corner of the page. 

For detailed information on Splitting and managing page modifications please review this Help Center article: How do I Modify a Document? - Splitting, Updating, Viewing, Rotating, Deleting