diff --git a/src/Button/CopyButton/CopyButton.tsx b/src/Button/CopyButton/CopyButton.tsx
index 53b088b4a4..9660b95584 100644
--- a/src/Button/CopyButton/CopyButton.tsx
+++ b/src/Button/CopyButton/CopyButton.tsx
@@ -70,7 +70,7 @@ const CopyButton: React.FC<CopyButtonProps> = ({
 
     const copy = feat.clone();
 
-    layers[0].getSource().addFeature(copy);
+    layers[0].getSource()?.addFeature(copy);
 
     AnimateUtil.moveFeature(
       map,
diff --git a/src/Button/DeleteButton/DeleteButton.tsx b/src/Button/DeleteButton/DeleteButton.tsx
index 6e6f01cab9..69d0db22b8 100644
--- a/src/Button/DeleteButton/DeleteButton.tsx
+++ b/src/Button/DeleteButton/DeleteButton.tsx
@@ -63,7 +63,7 @@ export const DeleteButton: React.FC<DeleteButtonProps> = ({
   const onFeatureSelect = (event: OlSelectEvent) => {
     onFeatureRemove?.(event);
     const feat = event.selected[0];
-    layers[0].getSource().removeFeature(feat);
+    layers[0].getSource()?.removeFeature(feat);
   };
 
   const finalClassName = className
diff --git a/src/Button/DigitizeButton/DigitizeButton.tsx b/src/Button/DigitizeButton/DigitizeButton.tsx
index 538a806a22..9483d665ba 100644
--- a/src/Button/DigitizeButton/DigitizeButton.tsx
+++ b/src/Button/DigitizeButton/DigitizeButton.tsx
@@ -21,6 +21,7 @@ import * as OlEventConditions from 'ol/events/condition';
 import OlGeometry from 'ol/geom/Geometry';
 
 import _isFunction from 'lodash/isFunction';
+import _isArray from 'lodash/isArray';
 
 import ToggleButton, { ToggleButtonProps } from '../ToggleButton/ToggleButton';
 import MapUtil from '@terrestris/ol-util/dist/MapUtil/MapUtil';
@@ -901,7 +902,7 @@ class DigitizeButton extends React.Component<DigitizeButtonProps, DigitizeButton
     }
 
     if (this._digitizeLayer) {
-      this._digitizeLayer.getSource().removeFeature(feat);
+      this._digitizeLayer.getSource()?.removeFeature(feat);
     }
 
     if (_isFunction(onFeatureRemove)) {
@@ -974,7 +975,7 @@ class DigitizeButton extends React.Component<DigitizeButtonProps, DigitizeButton
 
     if (feature.get('isLabel')) {
       this._digitizeTextFeature = feature;
-      let textLabel = '';
+      let textLabel: string | string[] = '';
 
       const featureStyle = this.digitizeStyleFunction(feature);
 
@@ -986,7 +987,7 @@ class DigitizeButton extends React.Component<DigitizeButtonProps, DigitizeButton
 
       this.setState({
         showLabelPrompt: true,
-        textLabel
+        textLabel: _isArray(textLabel) ? textLabel.join(' ') : textLabel
       });
     }
   };
diff --git a/src/Button/DrawButton/DrawButton.tsx b/src/Button/DrawButton/DrawButton.tsx
index 41ee783e35..8c1699574b 100644
--- a/src/Button/DrawButton/DrawButton.tsx
+++ b/src/Button/DrawButton/DrawButton.tsx
@@ -149,7 +149,7 @@ const DrawButton: React.FC<DrawButtonProps> = ({
     }
 
     const newInteraction = new OlInteractionDraw({
-      source: layer.getSource(),
+      source: layer.getSource() || undefined,
       type: type,
       geometryFunction: geometryFunction,
       style: drawStyle ?? DigitizeUtil.defaultDigitizeStyleFunction,
@@ -227,7 +227,7 @@ const DrawButton: React.FC<DrawButtonProps> = ({
 
     const onModalLabelCancelInternal = () => {
       onModalLabelCancel?.();
-      layer.getSource().removeFeature(digitizeTextFeature);
+      layer.getSource()?.removeFeature(digitizeTextFeature);
       setDigitizeTextFeature(null);
     };
 
diff --git a/src/Button/GeoLocationButton/GeoLocationButton.tsx b/src/Button/GeoLocationButton/GeoLocationButton.tsx
index a23a06b01d..119f0fc6ea 100644
--- a/src/Button/GeoLocationButton/GeoLocationButton.tsx
+++ b/src/Button/GeoLocationButton/GeoLocationButton.tsx
@@ -136,7 +136,7 @@ class GeoLocationButton extends React.Component<GeoLocationButtonProps> {
 
     if (showMarker) {
       this._markerFeature = new OlFeature();
-      this._geoLocationLayer.getSource().addFeature(this._markerFeature);
+      this._geoLocationLayer.getSource()?.addFeature(this._markerFeature);
     }
   }
 
@@ -151,7 +151,7 @@ class GeoLocationButton extends React.Component<GeoLocationButtonProps> {
 
     if (showMarker && !this._markerFeature) {
       this._markerFeature = new OlFeature();
-      this._geoLocationLayer.getSource().addFeature(this._markerFeature);
+      this._geoLocationLayer.getSource()?.addFeature(this._markerFeature);
     }
   }
 
@@ -241,7 +241,7 @@ class GeoLocationButton extends React.Component<GeoLocationButtonProps> {
       }
       if (this._markerFeature) {
         this._markerFeature = null;
-        this._geoLocationLayer.getSource().clear();
+        this._geoLocationLayer.getSource()?.clear();
       }
       return;
     }
@@ -257,8 +257,8 @@ class GeoLocationButton extends React.Component<GeoLocationButtonProps> {
       if (!this._markerFeature) {
         this._markerFeature = new OlFeature();
       }
-      if (!this._geoLocationLayer.getSource().getFeatures().includes(this._markerFeature)) {
-        this._geoLocationLayer.getSource().addFeature(this._markerFeature);
+      if (!this._geoLocationLayer.getSource()?.getFeatures().includes(this._markerFeature)) {
+        this._geoLocationLayer.getSource()?.addFeature(this._markerFeature);
       }
       const heading = this._geoLocation.getHeading() || 0;
       const speed = this._geoLocation.getSpeed() || 0;
diff --git a/src/Button/MeasureButton/MeasureButton.tsx b/src/Button/MeasureButton/MeasureButton.tsx
index ed14d196d7..6b1d235431 100644
--- a/src/Button/MeasureButton/MeasureButton.tsx
+++ b/src/Button/MeasureButton/MeasureButton.tsx
@@ -394,7 +394,7 @@ class MeasureButton extends React.Component<MeasureButtonProps> {
     const drawType = measureType === 'polygon' ? OlGeometryType.MULTI_POLYGON : OlGeometryType.MULTI_LINE_STRING;
 
     const drawInteraction = new OlInteractionDraw({
-      source: this._measureLayer.getSource(),
+      source: this._measureLayer.getSource() || undefined,
       type: drawType,
       maxPoints: maxPoints,
       style: new OlStyleStyle({
@@ -513,7 +513,9 @@ class MeasureButton extends React.Component<MeasureButtonProps> {
 
     this._eventKeys.click = map.on('click', (e: OlMapBrowserEvent<MouseEvent>) => this.onMapClick(e));
 
-    if (!multipleDrawing && source.getFeatures().length > 0) {
+    const features = source?.getFeatures();
+
+    if (!multipleDrawing && features && features.length > 0) {
       this.cleanupTooltips();
       this.createMeasureTooltip();
 
@@ -521,7 +523,7 @@ class MeasureButton extends React.Component<MeasureButtonProps> {
         this.createHelpTooltip();
       }
 
-      source.clear();
+      source?.clear();
     }
   }
 
@@ -755,7 +757,7 @@ class MeasureButton extends React.Component<MeasureButtonProps> {
     this.cleanupTooltips();
 
     if (this._measureLayer) {
-      this._measureLayer.getSource().clear();
+      this._measureLayer.getSource()?.clear();
     }
   }
 
diff --git a/src/Button/ModifyButton/ModifyButton.tsx b/src/Button/ModifyButton/ModifyButton.tsx
index 41204d9b6b..972d755d32 100644
--- a/src/Button/ModifyButton/ModifyButton.tsx
+++ b/src/Button/ModifyButton/ModifyButton.tsx
@@ -238,7 +238,7 @@ export const ModifyButton: React.FC<ModifyButtonProps> = ({
   const onFeatureSelect = (event: OlSelectEvent) => {
     if (editLabel) {
       const labeled = event.selected.find(f => f.get('isLabel'));
-      setEditLabelFeature(labeled);
+      setEditLabelFeature(labeled || null);
     }
   };
 
diff --git a/src/Container/AddWmsPanel/AddWmsLayerEntry/AddWmsLayerEntry.tsx b/src/Container/AddWmsPanel/AddWmsLayerEntry/AddWmsLayerEntry.tsx
index ec0687dab4..1a33a42cb8 100644
--- a/src/Container/AddWmsPanel/AddWmsLayerEntry/AddWmsLayerEntry.tsx
+++ b/src/Container/AddWmsPanel/AddWmsLayerEntry/AddWmsLayerEntry.tsx
@@ -65,7 +65,7 @@ export class AddWmsLayerEntry extends React.Component<AddWmsLayerEntryProps, Add
     super(props);
     // TODO: getAttributions is not @api and returns a function in v6.5
     this.state = {
-      copyright: props.wmsLayer.getSource().getAttributions(),
+      copyright: props.wmsLayer.getSource()?.getAttributions() || null,
       queryable: props.wmsLayer.get('queryable')
     };
   }
diff --git a/src/HigherOrderComponent/TimeLayerAware/TimeLayerAware.tsx b/src/HigherOrderComponent/TimeLayerAware/TimeLayerAware.tsx
index 1c78845b1d..2bac52a17b 100644
--- a/src/HigherOrderComponent/TimeLayerAware/TimeLayerAware.tsx
+++ b/src/HigherOrderComponent/TimeLayerAware/TimeLayerAware.tsx
@@ -48,14 +48,14 @@ export function timeLayerAware<P>(WrappedComponent: React.ComponentType<P>, laye
     timeChanged = newValues => {
       layers.forEach(config => {
         if (config.isWmsTime) {
-          const parms = config.layer.getSource().getParams();
+          const parms = config.layer.getSource()?.getParams();
           const timeParam = findTimeParam(parms);
           if (_isArray(newValues)) {
             parms[timeParam] = `${newValues[0]}/${newValues[1]}`;
           } else {
             parms[timeParam] = `${newValues}`;
           }
-          config.layer.getSource().updateParams(parms);
+          config.layer.getSource()?.updateParams(parms);
         }
         if (config.customHandler) {
           config.customHandler(newValues);
diff --git a/src/LayerSwitcher/LayerSwitcher.tsx b/src/LayerSwitcher/LayerSwitcher.tsx
index 6cba0a3601..0b62846469 100644
--- a/src/LayerSwitcher/LayerSwitcher.tsx
+++ b/src/LayerSwitcher/LayerSwitcher.tsx
@@ -130,7 +130,7 @@ export class LayerSwitcher extends React.Component<LayerSwitcherProps, LayerSwit
       });
     } else {
       layerClone = new OlLayerTile({
-        source: layer.getSource(),
+        source: layer.getSource() || undefined,
         properties: {
           originalLayer: layer
         },
diff --git a/src/Panel/TimeLayerSliderPanel/TimeLayerSliderPanel.tsx b/src/Panel/TimeLayerSliderPanel/TimeLayerSliderPanel.tsx
index d43d6fabe5..71010d0842 100644
--- a/src/Panel/TimeLayerSliderPanel/TimeLayerSliderPanel.tsx
+++ b/src/Panel/TimeLayerSliderPanel/TimeLayerSliderPanel.tsx
@@ -260,7 +260,7 @@ export class TimeLayerSliderPanel extends React.Component<TimeLayerSliderPanelPr
   wmsTimeHandler = (value?: any) => {
     this._wmsTimeLayers.forEach(config => {
       if (config.layer && config.layer.get('type') === 'WMSTime') {
-        const params = config.layer.getSource().getParams();
+        const params = config.layer.getSource()?.getParams();
         let time;
         if (Array.isArray(value)) {
           time = value[0];
@@ -278,7 +278,7 @@ export class TimeLayerSliderPanel extends React.Component<TimeLayerSliderPanelPr
         } else {
           params.TIME = time.format(timeFormat);
         }
-        config.layer.getSource().updateParams(params);
+        config.layer.getSource()?.updateParams(params);
       }
     });
   };