Error Loading Add-Ins in Excel: Causes, Checks, and Fixes

If Excel says “Error loading add-ins,” first identify the add-in type, then disable it in Excel and restart: go to File > Options > Add-ins, select the relevant type in Manage, choose Go, and clear the checkbox for the add-in. If Excel opens normally afterward, update, repair, or reinstall that add-in before turning it back on.

What the error means

An add-in is an optional component that extends Excel, for example with new commands, data connections, custom functions, or automation. The message means Excel could not initialize or connect to an add-in it expected to load. It does not automatically mean the workbook is damaged, and it does not necessarily mean Excel itself is broken.

The cause depends on the add-in type. A Windows COM add-in may be incompatible with an Office update or another program. An Excel add-in file, often an .xlam or .xla file, may have moved or become unavailable. A web add-in may be unable to sign in or reach its service. Excel can also disable an add-in after repeated startup failures. The steps below focus on Excel for Microsoft 365 on Windows; Mac and Excel for the web have different add-in support.

Identify which add-in failed

Before changing settings, note the exact error text, the add-in name if shown, and when the message appears. A message on every launch points toward a startup add-in or a component Excel has disabled. An error only when opening a particular workbook may relate to a workbook-specific add-in, link, or automation feature.

In Windows desktop Excel, open File > Options > Add-ins. The list separates active, inactive, and disabled add-ins. The Type column helps identify what to check in the Manage menu at the bottom:

COM Add-ins are commonly installed by other Windows software. They are not supported by Excel for the web or Excel for Mac.
Excel Add-ins commonly include .xlam or .xla files and may be loaded from a folder or a file path.
Disabled Items lists add-ins Excel has turned off after a problem.
Office Add-ins, also called web add-ins, use web technologies and may depend on an account, network access, and organizational policy.

These categories are not interchangeable. If you cannot find the named item under one Manage option, check the others rather than assuming it is gone. The menus for web add-ins can vary with the Microsoft 365 update and account; common entry points include Home > Add-ins or Insert > Get Add-ins.

Disable the problem add-in and test Excel

Turn off only the add-in you suspect, then close and reopen Excel. For a COM add-in, use File > Options > Add-ins, select COM Add-ins beside Manage, choose Go, and clear its checkbox. For a file-based Excel add-in, select Excel Add-ins and choose Go. Removing the check mark prevents that add-in from loading; it does not uninstall the software or delete its file.

If you do not know which item is responsible, disable nonessential add-ins one at a time, restarting Excel after each change. This controlled test is more useful than switching everything off at once: it identifies the specific component and makes it easier to restore other tools. Keep a note of the original selections. If Excel will not stay open long enough to change them, use Safe Mode as described below.

For an Office web add-in, open the add-ins interface and remove or stop using the affected add-in if the option is available. If the problem appears only after signing in, test whether the account is the one that owns or is authorized to use it. A company-managed add-in may be deployed by an administrator, so a user might not be able to remove or repair it independently.

Check Disabled Items and startup files

Excel may automatically disable an add-in that made the program unstable. In File > Options > Add-ins, choose Disabled Items in the Manage list and select Go. If the item is there, record its name and check with the vendor or your IT team before enabling it. Re-enabling a component that repeatedly crashes Excel can bring the original problem back.

File-based add-ins can also fail because Excel is looking for a file that was moved, renamed, deleted, or stored on a disconnected network drive. Check the file location with the add-in provider and confirm that the location is available. Do not download a replacement from an unofficial site. If the add-in is supplied by your employer, ask whether it should be installed from a managed location.

Excel can load files from startup folders, including the folder specified by the At startup, open all files in setting under File > Options > Advanced > General. A damaged or outdated file in a startup location may trigger a load error even if it is not obvious in the regular add-in list. Do not delete unfamiliar files as a first step; identify their purpose or ask the person who manages the computer.

Use Safe Mode to isolate a startup conflict

On Windows, close Excel, press Windows key + R, type excel /safe, and press Enter. Safe Mode starts Excel with certain features and startup components bypassed, making it a useful diagnostic test. If the error disappears, an add-in or another startup customization is a likely cause. Safe Mode does not repair or remove the add-in, so return to normal Excel and disable items through Options.

If the error still appears in Safe Mode, the cause may be outside the add-in startup path, such as an Office installation issue, a policy, or a problem specific to a workbook. Safe Mode is a troubleshooting step, not a permanent way to use Excel. There is no equivalent excel /safe command for Excel on Mac; use its add-in controls and consult Microsoft or the add-in vendor for Mac-specific startup troubleshooting.

Update, repair, or reinstall the add-in

Once you have isolated the failing component, use a fix suited to its type. Check the add-in maker’s release notes and support page for compatibility with your current Microsoft 365 version. For a COM add-in installed with another application, update or repair that application using its official installer. If it is a company tool, have IT check whether the current version is approved and compatible before reinstalling it.

For an Excel add-in file, confirm that the file is present and that Excel can access its folder. If the vendor provides a clean current copy, follow its installation instructions rather than replacing files manually. For a web add-in, verify that Excel is signed in to the right account, that the service is available, and that the network or organization has not blocked it. Signing out and back in may help with an account issue, but it will not fix an expired license or a service outage.

Also install available Microsoft 365 updates: in Windows desktop Excel, go to File > Account > Update Options > Update Now, if that option is available. An organization may manage updates centrally, in which case the update controls can be restricted. If multiple add-ins fail at once, updating or repairing Office is more sensible than reinstalling each one individually.

Repair Microsoft 365 and check network or policy issues

If Excel continues to show errors with several add-ins, or the error remains after the failing add-in is disabled, consider repairing Office. In Windows, open Settings > Apps > Installed apps, find Microsoft 365, choose its menu, and select Modify. The available repair choices depend on the installation. Quick Repair is the less extensive option; Online Repair is more comprehensive and may require an internet connection and a fresh sign-in. Save your work and close Office apps first. Menu wording can vary by Windows release and installation type.

Web add-ins can fail for reasons unrelated to Excel’s local installation: a proxy or firewall may block the service, a sign-in token may have expired, or an administrator may have restricted add-ins or connected experiences. If the issue occurs only on a work or school account, ask IT whether the add-in is deployed, permitted, and available to your license. Avoid changing security settings or bypassing an organization’s controls to make an add-in load.

Security and compatibility precautions

An add-in can have broad access to data or run code, depending on its type and permissions. Treat unexpected add-ins and files cautiously, especially if they arrived in an email or came from an unfamiliar download site. Confirm the publisher and source before installing or enabling anything. A load error is not a reason to lower Excel’s macro security or trust every location.

Do not permanently disable antivirus protection, change Trust Center settings indiscriminately, or enable an unknown add-in just to clear a warning. If a legitimate file is blocked, verify it with the provider or your administrator and follow their approved process. Save a copy of important workbooks before testing an add-in that changes data, generates reports, or runs automation.

Excel for Mac and Excel for the web

Excel for Mac supports certain Excel add-ins and Office web add-ins, but it does not support Windows COM add-ins. If a Windows workflow depends on a COM add-in, it will not become available simply by opening the workbook on a Mac; ask the provider for a Mac-compatible version or an alternative. Mac menu names and update controls can differ from Windows, so use the add-in’s Mac instructions.

Excel for the web does not load desktop COM add-ins or desktop Excel add-in files in the same way as Windows Excel. It supports compatible Office web add-ins, subject to account and administrator settings. A workbook that relies on a desktop add-in may still open in a browser while features supplied by that add-in are unavailable. Use the desktop application or a supported alternative when those features are essential.

Frequently Asked Questions

Why does Excel keep saying “Error loading add-ins”?
Excel may be trying to start an outdated, damaged, unavailable, or incompatible add-in each time it opens. Check the add-in name, disabled items, and startup files, then disable the suspected item and restart Excel to see whether the message stops.

How do I find which add-in is causing the error?
Open File > Options > Add-ins and check the add-in categories and Disabled Items. If the cause is unclear, disable nonessential add-ins one at a time and restart after each change. Safe Mode can help establish whether a startup component is involved.

Will disabling an Excel add-in delete my data?
Clearing an add-in’s checkbox normally stops it from loading; it does not delete the add-in file or workbook data. However, a workbook may rely on an add-in’s custom functions or features, so those may no longer work until the component is restored. Keep a backup before testing tools that modify workbook contents.

Can I use a COM add-in in Excel for Mac or the web?
No. COM add-ins are a Windows desktop feature. Mac and web users need a compatible alternative, such as a supported Office web add-in or a version specifically made for that platform.

Should I reinstall Excel to fix an add-in error?
Usually, identify and repair or update the particular add-in first. If several add-ins fail or Excel continues to have problems after the add-in is disabled, update Microsoft 365 and consider its repair options before undertaking a full reinstall.

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