Troubleshooting

The mod does not validate your config. Bad entries are logged and skipped at best, and a misspelled field name inside a block is silently ignored by the game's .ini parser with no log line at all. So the order below matters - it goes from most to least common.

Turn the log on first

In XComEngine.ini:

[AbilityEditor.X2DLCInfo_AbilityEditor]
EnableDebug=true

Every applied change appears in Launch.log under the AbilityEditor tag:

SwordSlice ActionPointCost.iNumPoints changed from 2 to 1

If a field you expected is not in that log, it was never applied. That single fact resolves most problems here.

Nothing happened at all

1. Did you clear the config cache? Delete Documents\My Games\XCOM2 War of the Chosen\XComGame\Config. XCOM 2 caches config aggressively and will otherwise keep using the old values. This is the most common cause by a wide margin.
2. Missing Set guard. NumPoints=1 on its own does nothing; it needs SetNumPoints=true beside it. See Config syntax.
3. Broken line continuation. Every line but the last needs a trailing \\ with nothing after it. A broken one truncates the entry silently.
4. Wrong ability name. The log says AbilityEdit: Ability not found: <name>. Names are template names, not display names - the counter-attack from Bladestorm is BladestormAttack, not Bladestorm, and Bladestorm itself is a passive with no costs at all. If you meant to create that ability, Create=true is missing - or its CloneFrom source was not found, which the log says just before (CloneFrom source not found).
5. Single-object slot with no Class on an ability that has none. A Cooldown block without Class edits the existing cooldown; if the ability never had one, the block is a silent no-op. Name the Class to create one.

Something changed that I didn't ask for

Almost always a mode default. Every mode enum's first value is a Replace, and UnrealScript uses the first value when you omit the field.

• Costs listed without CostMode => every existing cost is wiped, keeping only what you listed.
• An Effects, Triggers or conditions entry without Mode => the whole target array is cleared first. With several entries each defaulting, each one re-clears, so only the last survives.
• A name array without its ...Mode => the game's array is replaced wholesale.

See Edit modes. The log records array wipes, so the debug output will show it.

There is a second-order effect worth knowing: after a wipe, an entry you did list is constructed fresh from its class, so every field you did not Set holds that class's defaults - not the ability's old values.

The field I want isn't listed anywhere

Some things genuinely cannot be edited per ability:

• The game reads the field from the class default, not from the ability. Usually the field is config on the game class and read as default.X. Editing the template's copy changes nothing, because the game never looks at it. These fields are global by design: set them in your own mod's XComGameCore.ini instead. For example:

[XComGame.X2Effect_Vengeance]
AIM_BASE=10

The reference pages list them as not editable, with the reason; Why isn't this editable? has the full list.

• The behaviour lives in native code or in a different config file entirely. Fire's tile-to-tile spread is one of these: it is native, and the only knob is the global LimitFireSpreadTiles in XComGameData.ini.

Inert keys in the game's own config

DefaultGameCore.ini ships ThreatenedBondmateAimBonusOutsideZone, BondmateTargetAimBonusOutsideZone and BondmateTargetCritBonusOutsideZone. No game class declares any of them - they do nothing, whatever you set. Also note X2Effect_SpectralZombie and X2Effect_SpectralArmyUnit have identically-named keys in separate sections; it is easy to edit the wrong one.

Load order

If an edit works alone but not alongside another mod, that mod is probably rewriting the same template after Ability Editor does. Edits are applied in OnPostTemplatesCreated; a mod that runs later wins.

Ability Editor ships a commented run-order hint in XComGame.ini:

[AbilityEditor CHDLCRunOrder]
; +RunAfter=LWOverhaul

Uncomment and adapt it to force Ability Editor to run after a specific overhaul mod. This uses the Community Highlander's run-order mechanism, so it requires the Highlander to be installed.

I edited a class from another mod and nothing resolved

Unqualified class names are assumed to be base game - X2Effect_Foo becomes XComGame.X2Effect_Foo. Qualify cross-mod classes with their package:

Class="MyModPackage.X2Effect_Foo"

The log reports AbilityEdit: Failed to load <family> class: <name> when a class cannot be resolved. If the class loads but has no dedicated editor, it still accepts its family's shared fields - and for conditions, that shared set is empty, so nothing but Class and Mode will apply.