This means the WinZip plugin for Word or Excel cannot load the shared Office Interop libraries it depends on. Repairing Office resolves it. Jump to your situation below or work through the methods in order.
The WinZip Express for Office FileLoadException occurs when the WinZip plugin for Microsoft Word or Excel cannot load the dependent Interop libraries it needs to run inside Office. These Office Interop assemblies are shared components, and when they are missing, unregistered, or the wrong version, the plugin fails to load and throws a FileLoadException. The primary fix is to repair Microsoft Office through Control Panel (Programs, Microsoft Office, Change, Repair), which re-registers the shared Interop files the plugin depends on. If the plugin itself is at fault, updating or reinstalling WinZip restores it, and ensuring the required .NET and VSTO runtime is present covers the case where the supporting framework is missing. Once the Interop libraries load correctly, the WinZip Office plugin works again.
The WinZip Express plugin runs inside Office and relies on Office's Interop libraries to talk to Word and Excel. A FileLoadException means it could not load one of those dependent assemblies, so the plugin cannot start.
That happens when the shared Interop files are missing, unregistered, or a mismatched version. Repairing Office re-registers them, which is why it is the main fix. Reinstalling WinZip and confirming the supporting runtime cover the cases where the plugin or framework rather than Office is the problem.
“A FileLoadException from WinZip Express for Office means the plugin cannot load the Office Interop libraries it leans on. Those are shared Office components, so when they go missing or get unregistered, the plugin cannot start. The fix that works most often is simply repairing Office from Control Panel, which re-registers those Interop files. If the plugin itself is damaged I reinstall WinZip, and I make sure the .NET and VSTO runtime it needs is actually installed.”
The FileLoadException means the WinZip Office plugin cannot load its Interop libraries. Repair Microsoft Office from Control Panel to re-register the shared Interop files, update or reinstall WinZip if the plugin is damaged, and confirm the required .NET and VSTO runtime is installed.
If repairing Office and reinstalling WinZip do not clear the FileLoadException, the exact assembly and version it fails to load appears in the exception detail or the Windows event log; that name pinpoints which Interop or runtime component to reinstall. You can also submit your error to us for a tailored fix.
