diff --git a/src/datasources/db/utils.ts b/src/datasources/db/utils.ts
index 366ad83..1c9282b 100644
--- a/src/datasources/db/utils.ts
+++ b/src/datasources/db/utils.ts
@@ -1,6 +1,5 @@
 import { Connection, EntityManager, ObjectType } from 'typeorm';
 import { Lockable } from '../../model/CargoBike';
-import { GraphQLError } from 'graphql';
 import { ActionLog, Actions } from '../../model/ActionLog';
 import { UserInputError } from 'apollo-server-express';
 
@@ -24,11 +23,11 @@ export function genDateRange (struct: any) {
  * @param dataSources
  * @param req user request
  */
-export function isLocked (parent: any, { dataSources, req }: { dataSources: any; req: any }) {
+export function isLocked (parent: any, { req }: { req: any }) {
     return req.userId !== parent.lockedBy && new Date() <= new Date(parent.lockedUntil);
 }
 
-export function isLockedByMe (parent: any, { dataSources, req }: { dataSources: any; req: any }) {
+export function isLockedByMe (parent: any, { req }: { req: any }) {
     return req.userId === parent.lockedBy && new Date() <= new Date(parent.lockedUntil);
 }
 
@@ -47,10 +46,6 @@ export async function deleteEntity (connection: Connection, target: ObjectType<L
 }
 
 export class LockUtils {
-    static getToken (req: any) : string {
-        return req.headers.authorization?.replace('Bearer ', '');
-    }
-
     static async findById (connection: Connection, target: ObjectType<Lockable>, alias: string, id: number): Promise<Lockable> {
         return await connection.getRepository(target)
             .createQueryBuilder(alias)
@@ -89,40 +84,6 @@ export class LockUtils {
         return await this.findById(connection, target, alias, id);
     }
 
-    static async unlockEntity_old (connection: Connection, target: ObjectType<Lockable>, alias: string, id: number, userId: number): Promise<boolean> {
-        const lock = await connection.getRepository(target)
-            .createQueryBuilder(alias)
-            .select([
-                alias + '.lockedUntil',
-                alias + '.lockedBy'
-            ])
-            .where('id = :id', {
-                id: id
-            })
-            .andWhere(alias + '.lockedUntil > CURRENT_TIMESTAMP')
-            .getOne();
-        if (!lock?.lockedUntil) {
-            // no lock
-            return true;
-            // eslint-disable-next-line eqeqeq
-        } else if (lock?.lockedBy == userId) {
-            // user can unlock
-            await connection.getRepository(target)
-                .createQueryBuilder(alias)
-                .update()
-                .set({
-                    lockedUntil: null,
-                    lockedBy: null
-                })
-                .where('id = :id', { id: id })
-                .execute();
-            return true;
-        } else {
-            // entity is locked by other user
-            return false;
-        }
-    }
-
     static async unlockEntity (connection: Connection, target: ObjectType<Lockable>, alias: string, id: number, userId: number): Promise<Lockable> {
         await connection.getRepository(target)
             .createQueryBuilder(alias)
@@ -173,7 +134,8 @@ export class ActionLogger {
         }
         const ret :string[] = [];
         Object.keys(updates).forEach(value => {
-            if (typeof updates[value] === 'object' && !Array.isArray(updates[value]) && updates[value]) {
+            // sometimes updates[value] is an array, e.g. timePeriods that are saved as a simple array in postgres
+            if (updates[value] && typeof updates[value] === 'object' && !Array.isArray(updates[value])) {
                 Object.keys(updates[value]).forEach(subValue => {
                     ret.push(alias + '."' + value + subValue[0].toUpperCase() + subValue.substr(1).toLowerCase() + '"');
                 });
diff --git a/src/resolvers/cargoBikeResolver.ts b/src/resolvers/cargoBikeResolver.ts
index 4e290eb..363739a 100644
--- a/src/resolvers/cargoBikeResolver.ts
+++ b/src/resolvers/cargoBikeResolver.ts
@@ -118,8 +118,8 @@ export default {
                 return new GraphQLError('Insufficient Permissions');
             }
         },
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req }),
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req }),
         timeFrames (parent: any, __: any, { dataSources, req }: { dataSources: any, req: any }) {
             if (req.permissions.includes(Permission.ReadTimeFrame)) {
                 return dataSources.lendingStationAPI.timeFramesByCargoBikeId(parent.id);
@@ -151,8 +151,8 @@ export default {
                 return new GraphQLError('Insufficient Permissions');
             }
         },
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     BikeEvent: {
         cargoBike (parent: any, __: any, { dataSources, req }: { dataSources: any, req: any }) {
@@ -183,12 +183,12 @@ export default {
                 return new GraphQLError('Insufficient Permissions');
             }
         },
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     BikeEventType: {
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     Mutation: {
         createCargoBike: (_: any, { cargoBike }: { cargoBike: any }, { dataSources, req }: { dataSources: any, req: any }) => {
diff --git a/src/resolvers/contactInformationResolvers.ts b/src/resolvers/contactInformationResolvers.ts
index 0430680..46b215a 100644
--- a/src/resolvers/contactInformationResolvers.ts
+++ b/src/resolvers/contactInformationResolvers.ts
@@ -42,8 +42,8 @@ export default {
                 return new GraphQLError('Insufficient Permissions');
             }
         },
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     ContactInformation: {
         person: (parent: any, __: any, { dataSources, req }: { dataSources: any, req: any }) => {
@@ -53,8 +53,8 @@ export default {
                 return new GraphQLError('Insufficient Permissions');
             }
         },
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     Mutation: {
         createPerson: (_: any, { person }: { person: any }, { dataSources, req }: { dataSources: any, req: any }) => {
diff --git a/src/resolvers/lendingStationResolvers.ts b/src/resolvers/lendingStationResolvers.ts
index 8652530..adb6a41 100644
--- a/src/resolvers/lendingStationResolvers.ts
+++ b/src/resolvers/lendingStationResolvers.ts
@@ -77,8 +77,8 @@ export default {
                 return new GraphQLError('Insufficient Permissions');
             }
         },
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     LoanPeriod: {
         loanTimes  (parent: any) {
@@ -107,8 +107,8 @@ export default {
                 return new GraphQLError('Insufficient Permissions');
             }
         },
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     Mutation: {
         createLendingStation: (_: any, { lendingStation }:{ lendingStation: LendingStation }, { dataSources, req }:{dataSources: any, req: any }) => {
diff --git a/src/resolvers/participantResolvers.ts b/src/resolvers/participantResolvers.ts
index 1d3a8c0..70421b0 100644
--- a/src/resolvers/participantResolvers.ts
+++ b/src/resolvers/participantResolvers.ts
@@ -69,8 +69,8 @@ export default {
                 return new GraphQLError('Insufficient Permissions');
             }
         },
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     Engagement: {
         cargoBike (parent: any, _: any, { dataSources, req }: { dataSources: any, req: any }) {
@@ -101,8 +101,8 @@ export default {
             const str = (parent.dateRange as string).split(',')[1].replace(')', '');
             return (str.length > 0) ? str : null;
         },
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     Mutation: {
         createParticipant: (_: any, { participant }: { participant: any }, { dataSources, req }: { dataSources: any, req: any }) => {
diff --git a/src/resolvers/providerResolvers.ts b/src/resolvers/providerResolvers.ts
index 29fc9ac..0423cc8 100644
--- a/src/resolvers/providerResolvers.ts
+++ b/src/resolvers/providerResolvers.ts
@@ -55,8 +55,8 @@ export default {
                 return new GraphQLError('Insufficient Permissions');
             }
         },
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     Organisation: {
         provider: (parent: any, __: any, { dataSources, req }: { dataSources: any, req: any }) => {
@@ -80,8 +80,8 @@ export default {
                 return new GraphQLError('Insufficient Permissions');
             }
         },
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     Mutation: {
         createProvider: (_: any, { provider }: { provider: any }, { dataSources, req }: { dataSources: any, req: any }) => {
diff --git a/src/resolvers/workshopResolvers.ts b/src/resolvers/workshopResolvers.ts
index fe71587..6337a98 100644
--- a/src/resolvers/workshopResolvers.ts
+++ b/src/resolvers/workshopResolvers.ts
@@ -56,11 +56,12 @@ export default {
                 return new GraphQLError('Insufficient Permissions');
             }
         },
-        isLockedByMe: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLockedByMe(parent, { dataSources, req }),
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     WorkshopType: {
-        isLocked: (parent: any, __: any, { dataSources, req }: { dataSources: any; req: any }) => isLocked(parent, { dataSources, req })
+        isLockedByMe: (parent: any, __: any, { req }: { req: any }) => isLockedByMe(parent, { req }),
+        isLocked: (parent: any, __: any, { req }: { req: any }) => isLocked(parent, { req })
     },
     Mutation: {
         createWorkshop: (_: any, { workshop }: { workshop: number }, { dataSources, req }: { dataSources: any, req: any }) => {