Overview
This document describes why you cannot open a document for co-authoring.
Symptoms
When right-clicking a document and try choosing "Check Out for Co-authoring," you cannot see an option "Check Out for Co-authoring".
Details
Co-authoring only works with Microsoft Office documents like Word, Excel, and PowerPoint. Co-authoring does not work with other files, for example, PDF files.
Does not work with multi-file documents, or any files attached to it. Converting single-file documents to multi-file documents will break co-authoring.
User license must be "Named user license" or "Concurrent user license." Co-authoring does not work if a user has a "Read-only license."
Co-authoring requires that the user has "modify" -rights for the document. Co-authoring does not work if the user has only read access rights for the document.
If you still cannot see the "Check Out for Co-authoring" option, please see the reference documents on how to troubleshoot more.
Reference Documents
Co-authoring menu is not available in M-Files Desktop when the vault connection is using a proxy:
/article/Co-authoring-menu-is-not-available-in-M-Files-Desktop-when-vault-connection-is-using-proxy
How to collect client-side WOPI logs when Check Out for Co-authoring is not available:
/article/How-to-collect-client-side-WOPI-logs-when-Check-Out-for-Co-authoring-is-not-available
