Starting multi excel instance runs into problems whenever there is any add-in is enabled.

Question

I have a domain user needs to use multi excel instance every day. Recently when he tries to start a new excel instance, as long as there is any excel addin currently enabled, then the startup of 2nd instance will take long loading, eventually prompts error saying, "Excel is running into problems with 'c:\program files\microsoft office\root\office16\library\analysis\analys32.xll'. Disable this add-in and check for available updates. Do you want to disable it now?"

I looked around checking what the issue was and had no luck. Below are some items i tested.

1. The error is not limited to the particular add-in. All third-party plus excel native add-ins (Analys and Solver) will get this error prompt as long as there is any add-in enabled at the moment of starting the new excel instance.
2. The error will not occur when starting new excel instance in safe mode or simply just disabling all add-ins beforehand.
3. Other Windows user login the same PC and test the multi excel instances, no such error.
4. System restart, M365 Apps repair (quick and online), M365 Apps updates, Windows updates, M365 Apps reinstallation (From control panel and using Revo uninstaller).
5. Deleted excel registry "HKEY_USERS\Software\Microsoft\Office\16.0\Excel", no luck.
6. Same Windows user even login to a different PC (first time logging into this different PC), the same excel error still persists.
7. No roaming profile setup in the environment. Only some folder redirections for Desktop, Document, Downloads, Video, Pictures. User's \AppData\Roaming is still local only.
8. From Application log, event viewer, it captured excel running error every time the user trying to start new excel instance while there is any add-in enabled. On both PC.

9. At first, I raised a ticket from M365 Admin Panel, later the support based on the no.3 & 6 and told me they cannot handle any further. They told the issue should be lying under Windows support team, but they are just M365 online support team.

The M365 support told me to erase the local windows profile on that PC and relogin again to see if the issue is gone. But since i had the user to login on a different computer that he never logged into. I assume this is already equivalent to erasing the local profile plus login again. Yet the issue still persists.

Any idea of what happens and how to fix this? Thanks.

Answer 1

I have compared the gpreult /h report.html line by line for a few users and dont see any GPO object that is exclusively applied to the problematic user account. We do have policy to add Macro trusted locations in User Config firm-wide, this is applied to everyone, compared the GPO/registry regarding this policy and nothing difference.

I dont have policy to block unmanaged add-in or enforce any add-in load behavior. Tried to put another test computer to the default Computer OU where only the default domain policy is applied. The issue still happens for the same user. I created a domain user by copying the problematic user account. The same issue did not happen to this newly created account.

Have also compared the HKCU\Software\Classes\CLSID, I dont see anything special. Mostly just Windows Application like paints or may Bloomberg, but other users also have the similar directories and values.

I am running out of ideas.

Answer 2

Hi, I am also seeing this same issue with a couple of our users who use multiple instances of Excel. This started occurring in the last few weeks.

It appears that when the user tries to launch another instance of Excel via the Hold 'Alt' then click Excel icon, they also get the disable add-in message, and it in fact does not launch a new instance of Excel. It still loads another window of Excel in the existing Excel process.

One workaround that I have seen that gets it working is to run Excel through the Run command with the argument /x which is the command version to load a new instance. With this method, the new Excel instance loads correctly, and no issues or errors with loading the Add-ins.

So for now, I've simply created a desktop shortcut with a target like "C:*location to* Excel.exe" /x
This correctly loads a new instance of Excel as it should.

One of the affected user is still on Windows 10, and the other is on Windows 11, so I don't think it's a profile or policy related issue.
I do think it might be due to a recent Office 365 update, which might have broken the function to launch a new Excel session via the usual 'Alt-click' method.