Your situation is quite similar to mine in which I receive a message that reads something like this, “A program error has occurred. Quit Outlook and Microsoft Windows and then start again.”
That means various things: the program may need additional resources in order to run, it may be missing a vital file, your Outlook profile may be damaged, or the installation may be damaged.
Yeah, rebooting can temporarily solve this error if due to lack of system resources such as RAM, but if it still persists after reboot, it might involve some serious program errors such as damaged Outlook files, profiles, or installations.
If the problem has something to do with outlook profile, the approach for the fix will be creating a new profile, instructing it to use the .pst file which is the old one being used by the damage profile. To locate the path to the PST file, just read this guide on fixing
Microsoft Outlook Program Errors. If the profile fix still doesn’t solve your Outlook program errors, the errors are likely originating in Outlook itself. If you'll continue reading the guide, it will teach you how to repair damaged and mission Outlook program files.