diff --git a/packages/editor-ui/src/components/ExpressionInput.vue b/packages/editor-ui/src/components/ExpressionInput.vue
index d0c734e2c6..13c914ed17 100644
--- a/packages/editor-ui/src/components/ExpressionInput.vue
+++ b/packages/editor-ui/src/components/ExpressionInput.vue
@@ -265,7 +265,7 @@ export default mixins(
 
 					} else if (value.charAt(0) === '^') {
 						// Is variable
-						let displayValue = `{{${value.slice(1)}}}` as string | number | boolean | null;
+						let displayValue = `{{${value.slice(1)}}}` as string | number | boolean | null | undefined;
 						if (this.resolvedValue) {
 							displayValue = [null, undefined].includes(displayValue as null | undefined) ? '' : displayValue;
 							displayValue = this.resolveParameterString((displayValue as string).toString()) as NodeParameterValue;
diff --git a/packages/nodes-base/nodes/ActiveCampaign/ActiveCampaign.node.ts b/packages/nodes-base/nodes/ActiveCampaign/ActiveCampaign.node.ts
index 752cb46460..d19955eba0 100644
--- a/packages/nodes-base/nodes/ActiveCampaign/ActiveCampaign.node.ts
+++ b/packages/nodes-base/nodes/ActiveCampaign/ActiveCampaign.node.ts
@@ -841,7 +841,7 @@ export class ActiveCampaign implements INodeType {
 						source: this.getNodeParameter('source', i) as string,
 						email: this.getNodeParameter('email', i) as string,
 						totalPrice: this.getNodeParameter('totalPrice', i) as number,
-						currency: this.getNodeParameter('currency', i).toString().toUpperCase() as string,
+						currency: this.getNodeParameter('currency', i)!.toString().toUpperCase() as string,
 						externalCreatedDate: this.getNodeParameter('externalCreatedDate', i) as string,
 						connectionid: this.getNodeParameter('connectionid', i) as number,
 						customerid: this.getNodeParameter('customerid', i) as number,
diff --git a/packages/nodes-base/nodes/If.node.ts b/packages/nodes-base/nodes/If.node.ts
index 70bac4fb5f..447f985bac 100644
--- a/packages/nodes-base/nodes/If.node.ts
+++ b/packages/nodes-base/nodes/If.node.ts
@@ -234,27 +234,27 @@ export class If implements INodeType {
 		const compareOperationFunctions: {
 			[key: string]: (value1: NodeParameterValue, value2: NodeParameterValue) => boolean;
 		} = {
-			contains: (value1: NodeParameterValue, value2: NodeParameterValue) => value1.toString().includes(value2.toString()),
-			notContains: (value1: NodeParameterValue, value2: NodeParameterValue) => !value1.toString().includes(value2.toString()),
+			contains: (value1: NodeParameterValue, value2: NodeParameterValue) => (value1 || '').toString().includes((value2 || '').toString()),
+			notContains: (value1: NodeParameterValue, value2: NodeParameterValue) => !(value1 || '').toString().includes((value2 || '').toString()),
 			equal: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 === value2,
 			notEqual: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 !== value2,
-			larger: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 > value2,
-			largerEqual: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 >= value2,
-			smaller: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 < value2,
-			smallerEqual: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 <= value2,
+			larger: (value1: NodeParameterValue, value2: NodeParameterValue) => (value1 || 0) > (value2 || 0),
+			largerEqual: (value1: NodeParameterValue, value2: NodeParameterValue) => (value1 || 0) >= (value2 || 0),
+			smaller: (value1: NodeParameterValue, value2: NodeParameterValue) => (value1 || 0) < (value2 || 0),
+			smallerEqual: (value1: NodeParameterValue, value2: NodeParameterValue) => (value1 || 0) <= (value2 || 0),
 			regex: (value1: NodeParameterValue, value2: NodeParameterValue) => {
-				const regexMatch = value2.toString().match(new RegExp('^/(.*?)/([gimy]*)$'));
+				const regexMatch = (value2 || '').toString().match(new RegExp('^/(.*?)/([gimy]*)$'));
 
 				let regex: RegExp;
 				if (!regexMatch) {
-					regex = new RegExp(value2.toString());
+					regex = new RegExp((value2 || '').toString());
 				} else if (regexMatch.length === 1) {
 					regex = new RegExp(regexMatch[1]);
 				} else {
 					regex = new RegExp(regexMatch[1], regexMatch[2]);
 				}
 
-				return !!value1.toString().match(regex);
+				return !!(value1 || '').toString().match(regex);
 			},
 		};
 
diff --git a/packages/nodes-base/nodes/Salesforce/Salesforce.node.ts b/packages/nodes-base/nodes/Salesforce/Salesforce.node.ts
index e3146bc8aa..26981c2038 100644
--- a/packages/nodes-base/nodes/Salesforce/Salesforce.node.ts
+++ b/packages/nodes-base/nodes/Salesforce/Salesforce.node.ts
@@ -2214,7 +2214,7 @@ export class Salesforce implements INodeType {
 					const jsonParameters = this.getNodeParameter('jsonParameters', i) as boolean;
 					let variables = {};
 					if (jsonParameters) {
-						variables = this.getNodeParameter('variablesJson', i);
+						variables = this.getNodeParameter('variablesJson', i) as object;
 					} else {
 						// Input variables are defined in UI
 						const setInputVariable = this.getNodeParameter('variablesUi', i, {}) as IDataObject;
diff --git a/packages/nodes-base/nodes/Switch.node.ts b/packages/nodes-base/nodes/Switch.node.ts
index 2cf3ee598e..013c362dbc 100644
--- a/packages/nodes-base/nodes/Switch.node.ts
+++ b/packages/nodes-base/nodes/Switch.node.ts
@@ -468,27 +468,27 @@ export class Switch implements INodeType {
 		const compareOperationFunctions: {
 			[key: string]: (value1: NodeParameterValue, value2: NodeParameterValue) => boolean;
 		} = {
-			contains: (value1: NodeParameterValue, value2: NodeParameterValue) => value1.toString().includes(value2.toString()),
-			notContains: (value1: NodeParameterValue, value2: NodeParameterValue) => !value1.toString().includes(value2.toString()),
+			contains: (value1: NodeParameterValue, value2: NodeParameterValue) => (value1 || '').toString().includes((value2 || '').toString()),
+			notContains: (value1: NodeParameterValue, value2: NodeParameterValue) => !(value1 || '').toString().includes((value2 || '').toString()),
 			equal: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 === value2,
 			notEqual: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 !== value2,
-			larger: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 > value2,
-			largerEqual: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 >= value2,
-			smaller: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 < value2,
-			smallerEqual: (value1: NodeParameterValue, value2: NodeParameterValue) => value1 <= value2,
+			larger: (value1: NodeParameterValue, value2: NodeParameterValue) => (value1 || 0) > (value2 || 0),
+			largerEqual: (value1: NodeParameterValue, value2: NodeParameterValue) => (value1 || 0) >= (value2 || 0),
+			smaller: (value1: NodeParameterValue, value2: NodeParameterValue) => (value1 || 0) < (value2 || 0),
+			smallerEqual: (value1: NodeParameterValue, value2: NodeParameterValue) => (value1 || 0) <= (value2 || 0),
 			regex: (value1: NodeParameterValue, value2: NodeParameterValue) => {
-				const regexMatch = value2.toString().match(new RegExp('^/(.*?)/([gimy]*)$'));
+				const regexMatch = (value2 || '').toString().match(new RegExp('^/(.*?)/([gimy]*)$'));
 
 				let regex: RegExp;
 				if (!regexMatch) {
-					regex = new RegExp(value2.toString());
+					regex = new RegExp((value2 || '').toString());
 				} else if (regexMatch.length === 1) {
 					regex = new RegExp(regexMatch[1]);
 				} else {
 					regex = new RegExp(regexMatch[1], regexMatch[2]);
 				}
 
-				return !!value1.toString().match(regex);
+				return !!(value1 || '').toString().match(regex);
 			},
 		};
 
diff --git a/packages/workflow/src/Expression.ts b/packages/workflow/src/Expression.ts
index 6026c3eee0..7ad9a84ee9 100644
--- a/packages/workflow/src/Expression.ts
+++ b/packages/workflow/src/Expression.ts
@@ -205,7 +205,7 @@ export class Expression {
 			}
 
 			return returnData as NodeParameterValue[] | INodeParameters[];
-		} else if (parameterValue === null) {
+		} else if (parameterValue === null || parameterValue === undefined) {
 			return parameterValue;
 		} else {
 			// Data is an object
diff --git a/packages/workflow/src/Interfaces.ts b/packages/workflow/src/Interfaces.ts
index 7f1deea37b..bf0fc63e13 100644
--- a/packages/workflow/src/Interfaces.ts
+++ b/packages/workflow/src/Interfaces.ts
@@ -383,7 +383,7 @@ export interface INodeExecuteFunctions {
 
 
 // The values a node property can have
-export type NodeParameterValue = string | number | boolean;
+export type NodeParameterValue = string | number | boolean | undefined | null;
 
 export interface INodeParameters {
 	// TODO: Later also has to be possible to add multiple ones with the name name. So array has to be possible
diff --git a/packages/workflow/src/NodeHelpers.ts b/packages/workflow/src/NodeHelpers.ts
index f91889463b..15d4d4d28c 100644
--- a/packages/workflow/src/NodeHelpers.ts
+++ b/packages/workflow/src/NodeHelpers.ts
@@ -642,7 +642,7 @@ export function getNodeParameters(nodePropertiesArray: INodeProperties[], nodeVa
 			}
 
 			// Itterate over all collections
-			for (const itemName of Object.keys(propertyValues)) {
+			for (const itemName of Object.keys(propertyValues || {})) {
 				if (nodeProperties.typeOptions !== undefined && nodeProperties.typeOptions.multipleValues === true) {
 					// Multiple can be set so will be an array
 
diff --git a/packages/workflow/src/Workflow.ts b/packages/workflow/src/Workflow.ts
index 6386786a80..47e2fca9c5 100644
--- a/packages/workflow/src/Workflow.ts
+++ b/packages/workflow/src/Workflow.ts
@@ -380,8 +380,8 @@ export class Workflow {
 
 		const returnData: any = {}; // tslint:disable-line:no-any
 
-		for (const parameterName of Object.keys(parameterValue)) {
-			returnData[parameterName] = this.renameNodeInExpressions(parameterValue[parameterName], currentName, newName);
+		for (const parameterName of Object.keys(parameterValue || {})) {
+			returnData[parameterName] = this.renameNodeInExpressions(parameterValue![parameterName], currentName, newName);
 		}
 
 		return returnData;