When I was updating the french language file, I found out that there quite a few things that were not translated properly or missing a translation in the lang files.

Not properly translated things:

-Reconstruction master acheivement (achievement.actuallyadditions.getcristalsMilestone)
-Cristal Flux
-Empowered Cristals (blocks and items)
-Crystals and Reconstructors chapter (booklet.actuallyadditions.chapter.crystals.*)
-Solidified Experience (item.actuallyadditions.item_solidified_experience.name)
-Crystal armor and tools (includes AIOTs)
-Crystallised Oil (fluid.actuallyadditions.crystaloil)

Missing translation:

-"(Empowerer Recipe)","(Atomic Reconstructor Recipe)",
"(Coffee Maker Recipe)" and (Furnace Recipe)" in the booklet
-"Mod mode" in the advanced item laser relay interface
-"View Online" button
-"Small", tooltip of the small storage crate
-"Supersolid", tooltip of the big storage crate
-"No effect", tooltip of coffee cup
-"Click to search"
-"Blaze Stored", potion rings
-"filled slots", tooltip of sacks
-"Selected block:" tooltip of Handheld filler
-"Auto-Split items off/on" in double crusher and powered furnace

"Not translated properly"? All the ones in that list seem fine, you just have a typo in half of them yourself :p

What I mean by that is they does not get translated when switching languages.
For example, in french language, "Palis Crystal Helmet" is not replaced by "Casque en cristal de palis"

That.. doesn't make any sense O_o Are you sure you don't have a typo or have a space on one side of the equals sign?

Well for the palis crystal Helmet, I wrote this:

item.actuallyadditions.item_helm_cristal_blue.name=Casque en cristal de palis
There is no error there, right?

So... i set the language to german to see if this would happen and I found out that almost no item was translated, only potions rings gets partially translated to german :p

That's because no one is working on the german translation.

wait there is a german language file right?

Yea.

So if there is a german translation for the items why it is not working properly?

Because not all the items have a german translation, because no one is working on it.

Yeah but the items shown on the image above do have a german translation

info.actuallyadditions.booklet.manualName.1=Actually Additions
info.actuallyadditions.booklet.manualName.2=Handbuch

item.actuallyadditions.itemFoodDoughnut.name=Krapfen

item.actuallyadditions.itemDrillUpgradeFortune.name=Bohrerverbesserung: Glück I

item.actuallyadditions.itemFoodCheese.name=Käse

item.actuallyadditions.goldPaxel.name=Gold-AIEW

These are all the old localizations from pre-1.11..

Well these localizations are still in the 1.11.2 version of the mod aren't they?

no. All items got changed from camelCase to snake_case.

My bad :D
But the french localizations keys are identical to the english ones, so there is no reason they are not translated properly

That's really weird, I don't know why it would just happen with those items.