Fixes skill calculation.

source/module/actors/M5Character.ts

@@ -123,7 +123,7 @@ export class M5Character extends Actor {
 		ret.stats.poisonResistance = this.modResult(30 + Math.floor(ret.attributes.ko.value / 2))
 		ret.stats.enduranceBonus = Math.floor(ret.attributes.ko.value/10) + Math.floor(ret.attributes.st.value/20)
 
-		if (!skip.mods) {
+		if (!skip?.mods) {
 			const aggregate = new M5ModAggregate(data, ret)
 
 			context.items?.filter(item => item.type === "item").forEach(item => {
@@ -136,9 +136,10 @@ export class M5Character extends Actor {
 			})
 			
 			ret.skillMods = aggregate.calculate()
+			// TODO apply attribute and stat calculation to ret.
 		}
 
-		if (!skip.items) {	
+		if (!skip?.items) {	
 			context.items?.filter(item => item.type === "item").forEach(item => {
 				item.prepareDerivedData()
 
@@ -155,7 +156,7 @@ export class M5Character extends Actor {
 			})
 		}
 
-		if (!skip.skills) {
+		if (!skip?.skills) {
 			context.items?.filter(item => item.type === "skill").forEach(item => {
 				item.prepareDerivedData()
 				const skillMap = ret.skills[item.system.type]
@@ -168,7 +169,7 @@ export class M5Character extends Actor {
 			})
 		}
 
-		if (!skip.weapons) {	
+		if (!skip?.weapons) {	
 			context.items?.filter(item => item.type === "weapon").forEach(item => {
 				item.prepareDerivedData()
 
@@ -190,7 +191,7 @@ export class M5Character extends Actor {
 			})
 		}
 
-		if (!skip.defensiveWeapons) {	
+		if (!skip?.defensiveWeapons) {	
 			context.items?.filter(item => item.type === "defensiveWeapon").forEach(item => {
 				item.prepareDerivedData()
 
@@ -210,7 +211,7 @@ export class M5Character extends Actor {
 			})
 		}
 
-		if (!skip.armor) {	
+		if (!skip?.armor) {	
 			context.items?.filter(item => item.type === "armor").forEach(item => {
 				item.prepareDerivedData()
 
@@ -227,7 +228,7 @@ export class M5Character extends Actor {
 			})
 		}
 
-		if (!skip.spells) {	
+		if (!skip?.spells) {	
 			context.items?.filter(item => item.type === "spell").forEach(item => {
 				item.prepareDerivedData()