External links hiding in conditional formatting — find and remove them
Every visible formula in this workbook is clean, and Break Links still didn't clear the warning. That's because one of your conditional formatting rules contains a formula that references another workbook — and Manage Rules is the only place that formula is visible.
Where this formula actually lives
A formula-based conditional formatting rule is stored with the rule itself, not in any cell. You can format an entire range so every cell in it turns red when some condition is true, and that condition can reference a completely different workbook. Nothing about the formatting — the red fill, the bold text — tells you where the underlying comparison is pointing.
Why it's easy to miss
Searching with Ctrl+F, even set to search formulas, never reaches conditional formatting rules — they aren't cell content. Break Links and Edit Links manage external references inside worksheet cells; a rule's comparison formula sits in a completely separate part of the file structure, so it keeps its external pointer no matter how many times you break links elsewhere.
How to find the specific rule
Open Home → Conditional Formatting → Manage Rules, and set “Show formatting rules for” to “This Worksheet” — then repeat per sheet, since rules are sheet-scoped. Read the Applies to range and the rule's formula for each entry; any formula containing a bracketed filename like [Budget.xlsx] is your culprit. Delete the rule, rebuild it referencing a local range, or copy the external values in first. Upload the file below to get every conditional formatting rule's formula listed in one pass, across every sheet, instead of opening Manage Rules sheet by sheet.