Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
I have the same problem with Office Pro Plus 2016 when using Outlook. I've tried the fix using Control Panel->Programs->Programs and Features-> MS Office -> change -> quick/online repair but this is temporary. After 1-2 days the update splash screen will reappear and I get again the same error.
I found a different temporary "fix" that doesn't involve constant "repair" of the installation nor restarting the computer. Open the Task Manager, go to Services tab and Stop the "ClickToRunSvc" service. This will kill the "OfficeClickToRun.exe" process which seems to be responsible with the update splash screen. I could then open the Outlook app, go to File --> Office Account --> Office Updates and manually update the product. It shows now "Version 2102 (Build 13801.20294 Click-to-Run)". Still this doesn't seem to fix it permanently as the update splash screen (and the associated error) reappears after a day or two, but maybe MS can have a look into what this service is doing wrong when trying to update the Office products.