VSTO Word Add-In causing 45 second load times RRS feed

  • Question

  • I'd appreciate help determining why my Word VSTO Add-In is causing 45 second load times.

    The Add-In is used by multiple customers, only one of which experience this issue. I can not reproduce the problem on any of my test environments. (all running Windows 10, Office 365)


    • v35 of the Add-In works fine (built back in March).
    • After the customer installs v55 the problem starts (built in July).
    • I've incrementally removed all my code, nuget packages, reference (everything) from the Add-In and the problem persists.
    • I've removed my Add-In and create a new WordAddin1 project. The 45 second problem occurs when this Add-In is installed at the customer.
    • If I rebuild v35 today and run on the customer machine it works fine.
    • I have established that the 45 seconds happens BEFORE my Add-In code get's a chance to run.
    • I have run fuslogvw.exe to determine if any dependencies are causing timeouts (they aren't)
    • I have run performance monitoring to ensure that CPU, Memory, Disk, Network traffic are at acceptable levels (they are)
    • I have run Telerik Fiddler to monitor traffic and can see multiple calls (4) to Windows Update that time out (the customer pushes out updates via SCCM and does not get updates from Windows Update)
    • 2 of those Windows Update calls and timeouts happen when I disable my Add-In and Word opens within 5 seconds.

    How can I better understand what Word is doing during that 45 seconds? It's a black box that I can't seem to peer into.

    Any help greatly appreciated

    Thursday, August 13, 2020 4:13 AM

All replies

  • I have established that the 45 seconds happens BEFORE my Add-In code get

    Does the customer have any other add-ins? Historically different version of .Net addins used to compete for the loading of the version of .Net. Unclear if that is similar or can happen w/the lastest version. 

    William Wegerson (www.OmegaCoder.Com)

    Friday, August 14, 2020 4:46 PM
  • Thanks for your reply William.

    I disabled the other Add-ins and the problem persisted.

    The Word 'splash screen' indicates that it is loading my add-in and the splash screen doesn't change for 45 seconds.

    Monday, August 17, 2020 1:39 AM