ERR 99
Canon DSLR Camera
Severity: CriticalWhat Does This Error Mean?
ERR 99 is Canon's general catch-all error — it can mean almost anything went wrong. It is the most common and most frustrating Canon DSLR error. Start by turning the camera off, removing the lens and battery, waiting 30 seconds, then reassembling.
Affected Models
- Canon EOS Rebel T7
- Canon EOS Rebel T8i
- Canon EOS 5D Mark IV
- Canon EOS 6D Mark II
- Canon EOS 90D
- Canon EOS 80D
- Canon EOS 7D Mark II
- Most Canon DSLRs
Common Causes
- Dirty lens contacts — the most common cause
- Incompatible or faulty third-party lens
- Corrupted memory card
- Shutter mechanism nearing end of life
- Internal electronic malfunction
- Battery not making good contact
How to Fix It
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Turn off the camera, remove the lens, and clean the gold lens contacts.
Use a clean, dry microfiber cloth or a pencil eraser to gently clean the gold contacts on both the lens and the camera body. Dirty contacts are the #1 cause of ERR 99.
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Remove the battery and memory card, wait 30 seconds, then reinsert.
This performs a full power reset, clearing temporary electronic glitches. Make sure the battery is fully charged.
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Try a different lens to isolate the problem.
If ERR 99 only appears with one lens, that lens has a fault. If it appears with all lenses, the camera body is the issue.
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Try a different memory card.
A corrupted or incompatible card can trigger ERR 99. Format a known-good card in the camera (not on a computer) and test.
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If the error persists with all lenses and cards, the shutter may be failing.
Canon shutters are rated for 100,000-300,000 actuations depending on the model. A worn shutter mechanism causes ERR 99 intermittently, then more frequently.
Frequently Asked Questions
Why is ERR 99 so vague?
Canon designed ERR 99 as a catch-all for any error that does not have a specific code. This makes diagnosis frustrating — it could be the lens, card, shutter, electronics, or battery. The systematic elimination process (try different lens, different card, etc.) is the only way to narrow it down.
Do mirrorless Canon cameras also show ERR 99?
No. ERR 99 is specific to Canon DSLRs. Canon mirrorless cameras (EOS R series) use a different error system with more specific error numbers like ERR 20, ERR 70, etc.