Debugging GAS¶

Ability won't activate?
├─ Is the ability granted?
│  └─ No → Grant it (GiveAbility). Check showdebug.
├─ Check showdebug abilitysystem → is it in the ability list?
│  └─ No → It's not granted. Fix granting logic.
├─ Does the ability have Activation Blocked Tags?
│  └─ Check if the owning ASC has any of those tags right now.
├─ Does the ability have Activation Required Tags?
│  └─ Check if the owning ASC is MISSING any of those tags.
├─ Is the ability on cooldown?
│  └─ Check Active Effects for the cooldown GE.
├─ Can the owner afford the cost?
│  └─ Check the relevant attribute value vs the cost GE.
├─ Is the Net Execution Policy correct?
│  └─ ServerOnly won't run on clients. LocalOnly won't run on server.
├─ Does CanActivateAbility return true?
│  └─ Override it, add logging, check what fails.
└─ Check the output log for "AbilitySystem" warnings.

Effect doesn't modify attribute?
├─ Is the effect actually applied?
│  └─ Check showdebug → Active Effects list.
├─ Is the modifier targeting the right attribute?
│  └─ Check the GE's modifier setup.
├─ Is the modifier magnitude non-zero?
│  └─ Check SetByCaller values, curve lookups, MMC output.
├─ Are there tag requirements filtering the modifier?
│  └─ Check source/target tag requirements on the modifier.
└─ Is the attribute on the target's AttributeSet?
    └─ Missing attributes cause silent failures.

Cue doesn't play?
├─ Is the cue tag set correctly on both the GE and the cue notify?
├─ Is the cue in a scanned path?
│  └─ Check GameplayCueNotifyPaths in project settings.
├─ Is the cue loaded?
│  └─ Check for "missing gameplay cue" log warnings.
├─ Are cues suppressed?
│  └─ Check ShouldSuppressGameplayCues.
└─ Is this a local-only cue on a non-local client?
    └─ Replicated cues need to go through the server.