components/application-mgt/io.entgra.device.mgt.core.application.mgt.core/src/main/java/io/entgra/device/mgt/core/application/mgt/core/impl/SubscriptionManagerImpl.java

@@ -707,6 +707,18 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
         }
     }
 
+    private <T> void validatePendingAppSubscription(List<Device> devices, SubscribingDeviceIdHolder subscribingDeviceIdHolder) throws BadRequestException{
+        Set<DeviceIdentifier> deviceIdentifiers = devices.stream()
+            .map(device -> new DeviceIdentifier(device.getDeviceIdentifier(), device.getType()))
+            .collect(Collectors.toSet());
+        Set<DeviceIdentifier> skippedDevices = subscribingDeviceIdHolder.getSkippedDevices().keySet();
+        if (skippedDevices.containsAll(deviceIdentifiers) && deviceIdentifiers.containsAll(skippedDevices)) {
+               String msg = "All devices in the subscription have pending operations for this application.";
+                log.error(msg);
+                throw new BadRequestException(msg);
+            }
+    }
+
     /**
      * This method perform given action (i.e APP INSTALL or APP UNINSTALL) on given set of devices.
      *
@@ -741,6 +753,7 @@ public class SubscriptionManagerImpl implements SubscriptionManager {
         Map<String, List<DeviceIdentifier>> deviceIdentifierMap = new HashMap<>();
 
         if (SubAction.INSTALL.toString().equalsIgnoreCase(action)) {
+            validatePendingAppSubscription(devices, subscribingDeviceIdHolder);
             deviceIdentifiers.addAll(new ArrayList<>(subscribingDeviceIdHolder.getAppInstallableDevices().keySet()));
             deviceIdentifiers.addAll(new ArrayList<>(subscribingDeviceIdHolder.getAppReInstallableDevices().keySet()));
             if (!isOperationReExecutingDisabled) {