my error text:
App Inventor is unable to compile this project.
The compiler error output was
[ReadBuildInfo] Starting Task
[ReadBuildInfo] Task succeeded in 0.003 seconds
[LoadComponentInfo] Starting Task
[LoadComponentInfo] INFO: Generating assets...
[LoadComponentInfo] Component assets needed, n = 0
[LoadComponentInfo] INFO: Generating activities...
[LoadComponentInfo] Component activities needed, n = 1
[LoadComponentInfo] Component activity metadata needed, n = 0
[LoadComponentInfo] INFO: Generating broadcast receivers...
[LoadComponentInfo] Component content providers needed, n = 0
[LoadComponentInfo] INFO: Generating libraries...
[LoadComponentInfo] Libraries needed, n = 0
[LoadComponentInfo] Component metadata needed, n = 0
[LoadComponentInfo] INFO: Generating Android minimum SDK...
[LoadComponentInfo] INFO: Generating native libraries...
[LoadComponentInfo] Native Libraries needed, n = 0
[LoadComponentInfo] INFO: Generating permissions...
[LoadComponentInfo] INFO: Component "com.google.appinventor.components.runtime.Ball" does not specify permissionConstraints
[LoadComponentInfo] INFO: Component "com.google.appinventor.components.runtime.BluetoothClient" does not specify permissionConstraints
[LoadComponentInfo] INFO: Component "com.google.appinventor.components.runtime.Button" does not specify permissionConstraints
[LoadComponentInfo] INFO: Component "com.google.appinventor.components.runtime.Canvas" does not specify permissionConstraints
[LoadComponentInfo] INFO: Component "com.google.appinventor.components.runtime.Form" does not specify permissionConstraints
[LoadComponentInfo] INFO: Component "com.google.appinventor.components.runtime.HorizontalArrangement" does not specify permissionConstraints
[LoadComponentInfo] INFO: Component "com.google.appinventor.components.runtime.Label" does not specify permissionConstraints
[LoadComponentInfo] INFO: Component "com.google.appinventor.components.runtime.ListPicker" does not specify permissionConstraints
[LoadComponentInfo] INFO: Component "com.google.appinventor.components.runtime.TextBox" does not specify permissionConstraints
[LoadComponentInfo] INFO: Component "com.google.appinventor.components.runtime.VerticalArrangement" does not specify permissionConstraints
[LoadComponentInfo] usesLocation = False
[LoadComponentInfo] Permissions needed, n = 8
[LoadComponentInfo] Component services needed, n = 0
[LoadComponentInfo] INFO: Generating component broadcast receivers...
[LoadComponentInfo] Task succeeded in 0.007 seconds
[PrepareAppIcon] Starting Task
[PrepareAppIcon] INFO: Creating mipmap dirs...
[PrepareAppIcon] INFO: Generating icons...
[PrepareAppIcon] Generating icons for mipmap-mdpi
[PrepareAppIcon] Generating icons for mipmap-hdpi
[PrepareAppIcon] Generating icons for mipmap-xhdpi
[PrepareAppIcon] Generating icons for mipmap-xxhdpi
[PrepareAppIcon] Generating icons for mipmap-xxxhdpi
[PrepareAppIcon] Task succeeded in 1.294 seconds
[XmlConfig] Starting Task
[XmlConfig] INFO: Creating animation xml
[XmlConfig] Creating zoom_enter.xml
[XmlConfig] Creating fadeout.xml
[XmlConfig] Creating slide_v_exit.xml
[XmlConfig] Creating fadein.xml
[XmlConfig] Creating zoom_exit.xml
[XmlConfig] Creating slide_v_enter.xml
[XmlConfig] Creating zoom_exit_reverse.xml
[XmlConfig] Creating slide_v_enter_reverse.xml
[XmlConfig] Creating zoom_enter_reverse.xml
[XmlConfig] Creating slide_enter_reverse.xml
[XmlConfig] Creating slide_exit.xml
[XmlConfig] Creating hold.xml
[XmlConfig] Creating slide_enter.xml
[XmlConfig] Creating slide_v_exit_reverse.xml
[XmlConfig] Creating slide_exit_reverse.xml
[XmlConfig] INFO: Creating style xml
[XmlConfig] INFO: Creating provider_path xml
[XmlConfig] INFO: Creating network_security_config xml
[XmlConfig] INFO: Generating adaptive icon file
[XmlConfig] INFO: Generating round adaptive icon file
[XmlConfig] INFO: Generating adaptive icon background file
[XmlConfig] Task succeeded in 0.004 seconds
[CreateManifest] Starting Task
[CreateManifest] INFO: Reading project specs...
[CreateManifest] VCode: 1
[CreateManifest] VName: 1.0
[CreateManifest] Min SDK 7
[CreateManifest] INFO: Writing screen 'appinventor.ai_yuyang941106.bluetooth.Screen1'
[CreateManifest] Task succeeded in 0.0 seconds
[AttachNativeLibs] Starting Task
[AttachNativeLibs] Task succeeded in 0.001 seconds
[AttachAarLibs] Starting Task
[AttachAarLibs] Task succeeded in 0.153 seconds
[AttachCompAssets] Starting Task
[AttachCompAssets] Task succeeded in 0.0 seconds
[MergeResources] Starting Task
[MergeResources] Task succeeded in 0.193 seconds
[SetupLibs] Starting Task
[SetupLibs] Task succeeded in 0.0 seconds
[RunAapt] Starting Task
[RunAapt] Task succeeded in 0.842 seconds
[GenerateClasses] Starting Task
[GenerateClasses] INFO: Source File: appinventor/ai_yuyang941106/bluetooth/Screen1.yail
[GenerateClasses] INFO: Libraries Classpath = /tmp/kawa5792136851228806474.jar:/tmp/acra-4.4.06116416974152679848.jar:/tmp/AndroidRuntime5626300243156789007.jar:/tmp/annotation6252465077391112232.jar:/tmp/appcompat458133141126296512.jar:/tmp/asynclayoutinflater5969638713147770110.jar:/tmp/collection6799970068561001748.jar:/tmp/constraintlayout5036575240841205832.jar:/tmp/constraintlayout-solver996748203341637211.jar:/tmp/coordinatorlayout4396363321470749231.jar:/tmp/core8237106894401936646.jar:/tmp/core-common4377529827150076266.jar:/tmp/core-runtime4827426235902318013.jar:/tmp/cursoradapter393659381768923709.jar:/tmp/customview5036540034984239154.jar:/tmp/documentfile3181606791743359841.jar:/tmp/drawerlayout5417961209659248465.jar:/tmp/fragment2349855485128755398.jar:/tmp/interpolator1678935319446404270.jar:/tmp/legacy-support-core-ui8182291168226400843.jar:/tmp/legacy-support-core-utils111609451950635814.jar:/tmp/lifecycle-common5051818351433475010.jar:/tmp/lifecycle-livedata4421758780549737931.jar:/tmp/lifecycle-livedata-core3263969794388797500.jar:/tmp/lifecycle-runtime3556804775662855831.jar:/tmp/lifecycle-viewmodel6449873689474190119.jar:/tmp/loader32332717155851080.jar:/tmp/localbroadcastmanager7566688514798862416.jar:/tmp/print5812772795237147950.jar:/tmp/slidingpanelayout1094027977588793414.jar:/tmp/swiperefreshlayout6517551843109814738.jar:/tmp/vectordrawable9057209511299795917.jar:/tmp/vectordrawable-animated6883118657575064314.jar:/tmp/versionedparcelable8483355847522302761.jar:/tmp/viewpager6577034287173940033.jar:/tmp/1703093945892_0.6534238775730281-0/youngandroidproject/../build/classes:/tmp/android3976725106543680592.jar
[GenerateClasses] ERROR: Kawa compile has failed.
(compiling appinventor/ai_yuyang941106/bluetooth/Screen1.yail to appinventor.ai_yuyang941106.bluetooth.Screen1)
ERROR: appinventor/ai_yuyang941106/bluetooth/Screen1.yail line 218: duplicate declaration of 'back'
ERROR: appinventor/ai_yuyang941106/bluetooth/Screen1.yail line 218: (this is the previous declaration of 'back')
[GenerateClasses] ERROR: Can't find class file for Screen 'Screen1'
[GenerateClasses] Task errored in 2.166 seconds
my aia:
bluetooth.aia (86.0 KB)