Attached the screenshot.
Error log:
!ENTRY org.eclipse.e4.ui.workbench 4 0 2018-12-18 16:18:16.191
!MESSAGE
!STACK 0
java.lang.reflect.InvocationTargetException
at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:398)
at org.eclipse.jface.dialogs.ProgressMonitorDialog.run(ProgressMonitorDialog.java:481)
at com.kms.katalon.composer.execution.util.MobileDeviceUIProvider.newDownloadSDKProgress(MobileDeviceUIProvider.java:74)
at com.kms.katalon.composer.execution.util.MobileDeviceUIProvider.checkAndroidSDKExist(MobileDeviceUIProvider.java:66)
at com.kms.katalon.composer.execution.util.MobileDeviceUIProvider.lambda$0(MobileDeviceUIProvider.java:32)
at com.kms.katalon.composer.components.services.CallabelUISynchronize.lambda$0(CallabelUISynchronize.java:21)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:182)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4211)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3827)
at org.eclipse.jface.operation.ModalContext$ModalContextThread.block(ModalContext.java:165)
at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:369)
at org.eclipse.jface.dialogs.ProgressMonitorDialog.run(ProgressMonitorDialog.java:481)
at com.kms.katalon.composer.mobile.objectspy.components.LocalAppComposite.updateLocalDevices(LocalAppComposite.java:208)
at com.kms.katalon.composer.mobile.objectspy.dialog.MobileObjectSpyDialog.updateDeviceNames(MobileObjectSpyDialog.java:564)
at com.kms.katalon.composer.mobile.objectspy.dialog.MobileObjectSpyDialog.create(MobileObjectSpyDialog.java:551)
at org.eclipse.jface.window.Window.open(Window.java:783)
at com.kms.katalon.composer.mobile.objectspy.dialog.MobileObjectSpyDialog.open(MobileObjectSpyDialog.java:610)
at com.kms.katalon.composer.mobile.objectspy.handler.MobileSpyMobileHandler.openObjectSpyDialog(MobileSpyMobileHandler.java:84)
at com.kms.katalon.composer.mobile.objectspy.handler.MobileSpyMobileHandler.openAndAddElements(MobileSpyMobileHandler.java:68)
at com.kms.katalon.composer.mobile.objectspy.handler.MobileSpyMobileHandler.execute(MobileSpyMobileHandler.java:64)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:55)
at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:282)
at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:264)
at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:132)
at org.eclipse.e4.core.commands.internal.HandlerServiceHandler.execute(HandlerServiceHandler.java:152)
at org.eclipse.core.commands.Command.executeWithChecks(Command.java:494)
at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:488)
at org.eclipse.e4.core.commands.internal.HandlerServiceImpl.executeHandler(HandlerServiceImpl.java:210)
at org.eclipse.e4.ui.workbench.renderers.swt.HandledContributionItem.executeItem(HandledContributionItem.java:433)
at org.eclipse.e4.ui.workbench.renderers.swt.AbstractContributionItem.handleWidgetSelection(AbstractContributionItem.java:454)
at org.eclipse.e4.ui.workbench.renderers.swt.AbstractContributionItem$3.handleEvent(AbstractContributionItem.java:482)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4418)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1079)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4236)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3824)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$4.run(PartRenderingEngine.java:1121)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1022)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:150)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:693)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:610)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:148)
at com.kms.katalon.core.application.Application.internalRunGUI(Application.java:120)
at com.kms.katalon.core.application.Application.runGUI(Application.java:105)
at com.kms.katalon.core.application.Application.start(Application.java:63)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:388)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:243)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:673)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:610)
at org.eclipse.equinox.launcher.Main.run(Main.java:1519)
Caused by: java.lang.NullPointerException
at com.kms.katalon.execution.mobile.device.AndroidSDKDownloadManager.downloadUsingProxy(AndroidSDKDownloadManager.java:196)
at com.kms.katalon.execution.mobile.device.AndroidSDKDownloadManager.downloadAndExtract(AndroidSDKDownloadManager.java:267)
at com.kms.katalon.execution.mobile.device.AndroidSDKDownloadManager.downloadSDK(AndroidSDKDownloadManager.java:297)
at com.kms.katalon.execution.mobile.device.AndroidSDKDownloadManager.downloadAndInstall(AndroidSDKDownloadManager.java:163)
at com.kms.katalon.composer.execution.jobs.DownloadSDKProgress.run(DownloadSDKProgress.java:34)
at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:119)
Root exception:
java.lang.NullPointerException
at com.kms.katalon.execution.mobile.device.AndroidSDKDownloadManager.downloadUsingProxy(AndroidSDKDownloadManager.java:196)
at com.kms.katalon.execution.mobile.device.AndroidSDKDownloadManager.downloadAndExtract(AndroidSDKDownloadManager.java:267)
at com.kms.katalon.execution.mobile.device.AndroidSDKDownloadManager.downloadSDK(AndroidSDKDownloadManager.java:297)
at com.kms.katalon.execution.mobile.device.AndroidSDKDownloadManager.downloadAndInstall(AndroidSDKDownloadManager.java:163)
at com.kms.katalon.composer.execution.jobs.DownloadSDKProgress.run(DownloadSDKProgress.java:34)
at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:119)