I have an ice staff on the front bar with the new script. This is from the UESP website Debuffs: Applying Chilled status while actively holding a Frost Staff now applies Minor Brittle in addition to its other effects. Note that the Staff must be on your active bar when Chilled status is applied for this to proc. I have yet to see Brittle show in the CMX.

I have applied the brittle to the script but I am not proccing it at all, Brittle should show in the CMX at some point but nothing plus I have another addon that constantly shows Critical Damage and that stays at the same amount. I don`t know how else to explain but Brittle is not working on the new script and/or not at all.

I'll continue to test, but are you sure you're looking under (De-)buffs (Out) and not (De-)Buffs (In) in CMX? You say you have a buff tracker, but does that also track debuffs on the target?

Brittle is a debuff, after all, and is not reflected in your personal crit damage statistic. It is enemy specific, not player specific, so anyone attacking that target gets the extra damage, while if you attack another target, you don't get that crit damage.

My first test was to check the Brittle affix independent of anything ice related. This is Shocking Explosion with immobilize and Brittle, used with a fire staff to eliminate all other sources of Brittle. Brittle works just fine and registers properly in CMX. You can see the crit damage went up from 4842 to 5111, reflecting an increase in crit damage from 80% to 90% (1.9/1.8 = 1.0555, which is the same result as 5111/4842).

And here is Minor Brittle being procced by Chilled from Frost Touch with an ice staff, independent of the Explosion skill:

After I changed Shocking Explosion to Chilling Explosion and equipped an ice staff, CMX shows Chilling Explosion's frost damage proccing Chilled, which reapplies Minor Brittle (at 8.166s):

The first log is clearer in showing that Chilling Explosion can proc Chill, which then procs Brittle with an ice staff in hand. I included the second log there to show that despite the Minor Brittle being reapplied with Chill, the game correctly recognizes that Minor Brittle should still remain in effect because of the affix script's 20-second timer. It therefore properly drops only Minor Maim when Chill falls off.

Ok, it is working but not showing on the Critical Damage meter that I have on the UI. I`ll just have to check the CMX, Thank you!