I’ve been working with a customer doing some SharePoint integration with Dynamics365 and when we went to do the first step (which is the simplest) of turning it on.  I then went to access the Document Management section of the Account entity only to find that it was gone and not there.

This was a bummer.

In working to get this back, there are two solutions I looked at, both worked.

Adding the Navigation Link

There is a great article here on how to add the Navigation link back in for Documents.  I had never done this before, so this was interesting to do.  The directions here are straightforward and easy to follow;

https://community.dynamics.com/crm/b/debajitcrm/posts/documents-link-missing-in-navigation-pane-even-after-enabling-document-management-in-dynamics-version-9-0

Adding a Document Viewing pane into a SubGrid on the entity Form

This workaround is a little more involved.  But I have to say, I found it to be a very cool way to show documents directly on the form you are on.  In attempting to do this, I was able to get it to work with Dynamics365 and SharePoint Online, but not with Dynamics v9 and SharePoint on-Premise (perhaps as designed)?

Regardless, a very cool implementation if you want to save some clicks.

https://docs.microsoft.com/en-us/powerapps/maker/model-driven-apps/add-documents-tab-entity-main-form