I know this is an old thread, but there was some good information in here (and in other threads I came across). I am posting this as I had the same issue.
I've seen a lot of postings that suggested that QB Desktop wasn't compatible with Windows 10, and/or Office 365, possibly because of a particular Windows update or because Windows 10 comes with .NET 4.8. I support a lot of accountants and bookkeepers (plus I use QB myself) and I believe QB works just fine with all that - Win10, .NET 4.8, and Office 365). I would have my phone ringing all day if it wasn't...
This has been recommended earlier in this thread (Alex), but I want to emphasize it because it kind of (but not really) makes sense: uninstall and reinstall Quickbooks!
I found a document somewhere (written by a QB employee) that suggested that QB installs different components depending on what it detects is on the computer. (If you don't believe that, I don't blame you - it's a dumb way for an installer to work.) So, if you set up your computer and install QB BEFORE Office, it might not put the required components in place to work with Outlook. (Like I said, it's dumb. I"m not even sure it's true, but this worked for me.)
When I set up this computer for this client, I have no idea what order I installed the programs in. It's never been something I paid much attention to. Anyway, because I had tried about a zillion suggested fixes already, I did the uninstall and reinstall. Had to run File Doctor on the client's two company files because they wouldn't open. File Doctor said it couldn't find anything wrong, but they opened fine after.
Anyway, that's my long frustrating story. QB Support might tell you it has nothing to do with the installer not installing certain bits if it doesn't detect Office during the install. If they say so, believe them, not me. I didn't write the software, but I do support it. In the support business, WHY isn't near as important as HOW TO FIX.
I hope this helps someone out there...
