Why Word Co-authoring Returns ‘Upload Failed’ on Specific Document Types

When multiple users try to edit a Word document simultaneously, the co-authoring feature allows real-time collaboration. Some document types trigger an “Upload Failed” error during co-authoring, preventing any user from saving changes. This error occurs because Word enforces specific file format and storage requirements for co-authoring to function correctly. This article explains why certain document … Read more

Why Word Throws Diagnostic Code 30015-26 on Office Repair Attempts

When you try to repair Microsoft 365 or Office through Windows Settings or the Office installer, you may see error code 30015-26. This diagnostic code stops the repair process before it can complete. The error means the repair tool cannot access or modify the Office installation files. This article explains what causes error 30015-26 and … Read more

Word Showing Wrong Fonts Because of Font Substitution: Fix

When you open a document in Word and text appears in a different font than expected, font substitution is the likely cause. Word replaces missing fonts with available ones when the original font is not installed on your current system. This often happens when sharing documents between different computers or receiving files from others. This … Read more