is installed. While this is version 10.0, it is backward compatible with many solutions and is the only version actively supported for Office 2019/2021. Repair Office Installation : Sometimes the local assembly cache is corrupted. Use the Repair Office Settings > Apps to force a refresh of shared components. Microsoft Learn
By understanding that v90 refers to a 2008-era runtime, not a 2021 Office feature, you can safely resolve your error and get back to work. Microsoft may have moved on from these legacy tools, but with the right knowledge, you can keep them running securely for years to come.
If you encountered an application crash or a development bug referencing , you are dealing with a core legacy runtime assembly from Microsoft. Specifically, this string refers to Microsoft.Office.Tools.Common.v9.0.dll . This dynamic link library is a fundamental component of the Visual Studio Tools for Office (VSTO) Runtime infrastructure. microsoftofficetoolscommonv90 download 2021
Certain older but still functional tools – such as the , Microsoft Query , or third-party accounting/reporting add-ins – were compiled against the v90 runtime. Even if Office itself is new (Office 2019/2021), the add-in may still request microsoftofficetoolscommonv90.dll .
This error usually means your project targets an older build platform that is missing from newer installations. is installed
If you provide more context (e.g., what you expected that tool to do), I can give a more precise safe alternative.
2026-04-18 Prepared for: General Technical Inquiry Subject: Investigate the nature, legitimacy, and safety of the file/component named microsoftofficetoolscommonv90 Use the Repair Office Settings > Apps to
Follow these methods in sequence to resolve the prompt permanently without damaging your existing files. Method 1: Download the Official Microsoft Package
If you are still hitting roadblocks getting this component to register, I can help you dig deeper. To help me give you the best advice, let me know:
If the file was corrupted during a Windows update, a built-in repair can restore it. Open > Programs and Features .
: Official Microsoft downloads are hosted on domains such as microsoft.com or officecdn.microsoft.com . If you encounter a download from an unfamiliar site, it is likely unsafe. Recommended Actions
