diff --git a/src/main.mjs b/src/main.mjs
index dcb4bd20..fa69514f 100644
--- a/src/main.mjs
+++ b/src/main.mjs
@@ -23,7 +23,7 @@ import {ActiveEffectDataModel} from "./module/data/activeeffect.mjs";
 import {Trefferzone, Wunde, Zonenruestung, Zonenwunde} from "./module/data/Trefferzone.js";
 
 async function preloadHandlebarsTemplates() {
-    return loadTemplates([
+    return foundry.applications.handlebars.loadTemplates([
         // ui partials.
         'systems/DSA_4-1/templates/ui/partial-rollable-button.hbs',
         'systems/DSA_4-1/templates/ui/partial-rollable-weaponskill-button.hbs',
@@ -79,55 +79,55 @@ Hooks.once("init", () => {
 
     console.log("DSA 4.1 is ready for development!")
 
-    Actors.registerSheet('dsa41.character', CharacterSheet, {
+    foundry.documents.collections.Actors.registerSheet('dsa41.character', CharacterSheet, {
         types: ["character"],
         makeDefault: true,
         label: 'DSA41.CharacterLabels.Item'
     })
-    Actors.registerSheet('dsa41.creature', CreatureSheet, {
+    foundry.documents.collections.Actors.registerSheet('dsa41.creature', CreatureSheet, {
         types: ["creature"],
         makeDefault: true,
         label: 'DSA41.CreatureLabel.Item'
     })
-    Actors.registerSheet('dsa41.group', GroupSheet, {
+    foundry.documents.collections.Actors.registerSheet('dsa41.group', GroupSheet, {
         types: ["group"],
         makeDefault: true,
         label: 'DSA41.GroupLabel.Item'
     })
 
     // Register sheet application classes
-    Items.registerSheet('dsa41.skill', SkillSheet, {
+    foundry.documents.collections.Items.registerSheet('dsa41.skill', SkillSheet, {
         types: ["Skill"],
         makeDefault: true,
         label: 'DSA41.SkillLabels.Item',
     });
-    Items.registerSheet('dsa41.spell', SpellSheet, {
+    foundry.documents.collections.Items.registerSheet('dsa41.spell', SpellSheet, {
         types: ["Spell"],
         makeDefault: true,
         label: 'DSA41.SpellLabels.Item',
     });
-    Items.registerSheet('dsa41.advantage', VornachteilSheet, {
+    foundry.documents.collections.Items.registerSheet('dsa41.advantage', VornachteilSheet, {
         types: ["Advantage"],
         makeDefault: true,
         label: 'DSA41.VornachteilLabels.Item'
     })
-    Items.registerSheet('dsa41.equipment', AusruestungSheet, {
+    foundry.documents.collections.Items.registerSheet('dsa41.equipment', AusruestungSheet, {
         types: ["Equipment"],
         makeDefault: false,
         label: 'DSA41.AusruestungLabels.Item'
     })
-    Items.registerSheet('dsa41.liturgy', LiturgySheet, {
+    foundry.documents.collections.Items.registerSheet('dsa41.liturgy', LiturgySheet, {
         types: ["SpecialAbility"],
         makeDefault: true,
         label: 'DSA41.SpecialAbilityLabels.Item'
     })
-    Items.registerSheet('dsa41.specialAbility', SpecialAbilitySheet, {
+    foundry.documents.collections.Items.registerSheet('dsa41.specialAbility', SpecialAbilitySheet, {
         types: ["Liturgy"],
         makeDefault: true,
         label: 'DSA41.LiturgyLabels.Item'
     })
 
-    Items.registerSheet('dsa41.activeEffect', ActiveEffectSheet, {
+    foundry.documents.collections.Items.registerSheet('dsa41.activeEffect', ActiveEffectSheet, {
         types: ['ActiveEffect'],
         makeDefault: true,
         label: 'DSA41.ActiveEffectLabels.ActiveFfect'
diff --git a/src/module/sheets/ActiveEffectSheet.mjs b/src/module/sheets/ActiveEffectSheet.mjs
index 99211ed2..ef2c1d03 100644
--- a/src/module/sheets/ActiveEffectSheet.mjs
+++ b/src/module/sheets/ActiveEffectSheet.mjs
@@ -1,4 +1,4 @@
-export class ActiveEffectSheet extends ItemSheet {
+export class ActiveEffectSheet extends foundry.appv1.sheets.ItemSheet {
     /**@override */
     static get defaultOptions() {
         return foundry.utils.mergeObject(super.defaultOptions, {
diff --git a/src/module/sheets/characterSheet.mjs b/src/module/sheets/characterSheet.mjs
index 60176c50..743b73b0 100644
--- a/src/module/sheets/characterSheet.mjs
+++ b/src/module/sheets/characterSheet.mjs
@@ -3,7 +3,7 @@ import {ActionManager} from "./actions/action-manager.mjs";
 import {LiturgyData} from "../data/miracle/liturgydata.mjs";
 import {ModifyLiturgy} from "../dialog/modify-liturgy.mjs";
 
-export class CharacterSheet extends ActorSheet {
+export class CharacterSheet extends foundry.appv1.sheets.ActorSheet {
     /**@override */
     static get defaultOptions() {
         return foundry.utils.mergeObject(super.defaultOptions, {
@@ -841,7 +841,7 @@ export class CharacterSheet extends ActorSheet {
     activateListeners(html) {
         super.activateListeners(html);
 
-        const tabs = new Tabs({
+        const tabs = new foundry.applications.ux.Tabs({
             navSelector: ".paperdoll-tabs.tabs",
             contentSelector: ".sheet-body.paperdoll-sets",
             initial: "set" + (this.object.system.setEquipped + 1)
@@ -926,7 +926,7 @@ export class CharacterSheet extends ActorSheet {
             }
         })
 
-        new ContextMenu(html, '.talent.rollable', [
+        new foundry.applications.ux.ContextMenu(html[0], '.talent.rollable', [
             {
                 name: "Entfernen",
                 icon: '<i class="fa-solid fa-trash"></i>',
@@ -935,10 +935,12 @@ export class CharacterSheet extends ActorSheet {
                 },
                 condition: () => true
             }
-        ]);
+        ], {
+            jQuery: false
+        });
 
 
-        new ContextMenu(html, '.attribute.rollable', [
+        new foundry.applications.ux.ContextMenu(html[0], '.attribute.rollable', [
             {
                 name: "Anpassen",
                 icon: '<i class="fa-solid fa-pen"></i>',
@@ -947,7 +949,9 @@ export class CharacterSheet extends ActorSheet {
                 },
                 condition: () => true
             }
-        ]);
+        ], {
+            jQuery: false
+        });
 
         let handler = evt => {
             const talentId = evt.target.dataset.id
@@ -965,7 +969,7 @@ export class CharacterSheet extends ActorSheet {
             li.addEventListener("dragstart", handler, false);
         });
 
-        new ContextMenu(html, '.equipment', [
+        new foundry.applications.ux.ContextMenu(html[0], '.equipment', [
             {
                 name: "Aus dem Inventar entfernen",
                 icon: '<i class="fa-solid fa-trash"></i>',
@@ -975,9 +979,11 @@ export class CharacterSheet extends ActorSheet {
                 },
                 condition: () => true
             }
-        ]);
+        ], {
+            jQuery: false
+        });
 
-        new ContextMenu(html, '.equipped', [
+        new foundry.applications.ux.ContextMenu(html[0], '.equipped', [
             {
                 name: "Gegenstand vom Set entfernen",
                 callback: (event) => {
@@ -990,7 +996,9 @@ export class CharacterSheet extends ActorSheet {
                 },
                 condition: () => true
             }
-        ]);
+        ], {
+            jQuery: false
+        });
 
         html.on('click', '[data-operation="addWounds"]', async (evt) => {
             const {value} = evt.currentTarget.dataset
diff --git a/src/module/sheets/equipmentSheet.mjs b/src/module/sheets/equipmentSheet.mjs
index c5179223..d3d769f8 100644
--- a/src/module/sheets/equipmentSheet.mjs
+++ b/src/module/sheets/equipmentSheet.mjs
@@ -1,4 +1,4 @@
-export class AusruestungSheet extends ItemSheet {
+export class AusruestungSheet extends foundry.appv1.sheets.ItemSheet {
     /**@override */
     static get defaultOptions() {
         return foundry.utils.mergeObject(super.defaultOptions, {
diff --git a/src/module/sheets/groupSheet.mjs b/src/module/sheets/groupSheet.mjs
index 7e179037..3edff152 100644
--- a/src/module/sheets/groupSheet.mjs
+++ b/src/module/sheets/groupSheet.mjs
@@ -1,4 +1,4 @@
-export class GroupSheet extends ActorSheet {
+export class GroupSheet extends foundry.appv1.sheets.ActorSheet {
     /**@override */
     static get defaultOptions() {
         return foundry.utils.mergeObject(super.defaultOptions, {
diff --git a/src/module/sheets/liturgySheet.mjs b/src/module/sheets/liturgySheet.mjs
index 0a531f9a..3bb34124 100644
--- a/src/module/sheets/liturgySheet.mjs
+++ b/src/module/sheets/liturgySheet.mjs
@@ -1,4 +1,4 @@
-export class LiturgySheet extends ItemSheet {
+export class LiturgySheet extends foundry.appv1.sheets.ItemSheet {
     /**@override */
     static get defaultOptions() {
         return foundry.utils.mergeObject(super.defaultOptions, {
diff --git a/src/module/sheets/skillSheet.mjs b/src/module/sheets/skillSheet.mjs
index abffa724..0a3dc7e6 100644
--- a/src/module/sheets/skillSheet.mjs
+++ b/src/module/sheets/skillSheet.mjs
@@ -1,4 +1,4 @@
-export class SkillSheet extends ItemSheet {
+export class SkillSheet extends foundry.appv1.sheets.ItemSheet {
     /**@override */
     static get defaultOptions() {
         return foundry.utils.mergeObject(super.defaultOptions, {
@@ -52,7 +52,7 @@ export class SkillSheet extends ItemSheet {
         super.activateListeners(html);
 
         // Everything below here is only needed if the sheet is editable
-        if (!this.isEditable) return;
+        if (!this.isEditable)
     }
 
 }
\ No newline at end of file
diff --git a/src/module/sheets/specialAbilitySheet.mjs b/src/module/sheets/specialAbilitySheet.mjs
index a1c6bb08..533f1a8a 100644
--- a/src/module/sheets/specialAbilitySheet.mjs
+++ b/src/module/sheets/specialAbilitySheet.mjs
@@ -1,4 +1,4 @@
-export class SpecialAbilitySheet extends ItemSheet {
+export class SpecialAbilitySheet extends foundry.appv1.sheets.ItemSheet {
     /**@override */
     static get defaultOptions() {
         return foundry.utils.mergeObject(super.defaultOptions, {
diff --git a/src/module/sheets/vornachteilSheet.mjs b/src/module/sheets/vornachteilSheet.mjs
index bfc5ad0d..9db27543 100644
--- a/src/module/sheets/vornachteilSheet.mjs
+++ b/src/module/sheets/vornachteilSheet.mjs
@@ -1,4 +1,4 @@
-export class VornachteilSheet extends ItemSheet {
+export class VornachteilSheet extends foundry.appv1.sheets.ItemSheet {
     /**@override */
     static get defaultOptions() {
         return foundry.utils.mergeObject(super.defaultOptions, {