Font Substitution Will Occur Continue May 2026

Rarely, a font may be corrupted or restricted (e.g., licensed only for print, not screen). The system substitutes rather than failing completely.

Use this if you are writing a help article, a manual, or answering a user's question.

Title: What does "Font substitution will occur" mean?

This warning message appears when you open a document that contains fonts not currently installed on your device. The software is alerting you that it cannot display the original typography and will replace the missing fonts with defaults (such as Arial or Courier) or a "fallback" font. Font substitution will occur continue

Should you click "Continue"?

How to fix it:

| Type | Description | Example | |------|-------------|---------| | Silent substitution | User is not notified; happens automatically. | Browser replaces missing Arial with Nimbus Sans. | | Explicit substitution | System specifies which fallback font is used. | CSS font-family: "Helvetica", sans-serif; | | Algorithmic substitution | The renderer synthesizes a missing glyph or matches metrics. | Adobe InDesign’s Multiple Master fallback. | | Glyph-level substitution | Only one character replaced, rest of string keeps original font. | '€' missing → taken from another font. |

Modern systems typically combine these, with glyph-level substitution being the most common yet least understood. | Missing Font | Windows Substitute | macOS

A document may reference a font that is not installed on the rendering system. Examples:

5.1 Layout and Readability

5.2 Branding and Aesthetics

5.3 Accessibility and Internationalization Use this if you are writing a help

5.4 Performance and Bandwidth

5.5 Security Considerations

When the "Font substitution will occur continue" dialog box pops up, you have three immediate options. Do not simply click "Continue" blindly.