Trying to compile my app with Qt Creator

Question

Here is the bottom part of the compile output. I am stuck, please help. I can't seem to find anything regarding error 15. Also, when I compile and this error shows a .apk seems to still be created, but when I post to Google Play as an internal test the app crashes instantly and the icon has no name under it. I'm not very experienced with this program/code but I've gotten it to this point. Need some expert advice please.

23132854 res/layout/select_dialog_singlechoice_material.xml (OK - compressed)
23133325 res/layout/splash.xml (OK - compressed)
23133595 res/layout/support_simple_spinner_dropdown_item.xml (OK - compressed)
23133952 resources.arsc (OK)
Verification succesful
Signed
Verifies
Verified using v1 scheme (JAR signing): true
Verified using v2 scheme (APK Signature Scheme v2): true
Number of signers: 1
WARNING: META-INF/android.arch.core_runtime.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/android.arch.lifecycle_livedata-core.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/android.arch.lifecycle_runtime.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/android.arch.lifecycle_viewmodel.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/com.android.support_animated-vector-drawable.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/com.android.support_appcompat-v7.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/com.android.support_cardview-v7.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/com.android.support_customtabs.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/com.android.support_support-compat.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/com.android.support_support-core-ui.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/com.android.support_support-core-utils.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/com.android.support_support-fragment.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/com.android.support_support-media-compat.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/com.android.support_support-v4.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
WARNING: META-INF/com.android.support_support-vector-drawable.version not protected by signature. Unauthorized modifications to this JAR entry will not be detected. Delete or move the entry outside of META-INF/.
Warning: QML import could not be resolved in any of the import paths: QtQuick.Extras.Private.CppUtils
Warning: QML import could not be resolved in any of the import paths: QtQuick.Extras.Private.CppUtils
Warning: QML import could not be resolved in any of the import paths: QtQuick.Controls.Material.impl
Warning: QML import could not be resolved in any of the import paths: QtQuick.Controls.impl
Warning: QML import could not be resolved in any of the import paths: QtQuick.Controls.Fusion.impl
Warning: QML import could not be resolved in any of the import paths: QtQuick.Controls.Imagine.impl
Warning: QML import could not be resolved in any of the import paths:      QtQuick.Controls.Universal.impl
23:37:05: The process "C:\V-PlaySDK\V-Play\android_armv7\bin\androiddeployqt.exe" exited with code 15.
Error while building/deploying project Project_Name (kit: Android for armeabi-v7a (GCC 4.9, Qt 5.10.1 Android armv7 V-Play))
When executing step "Build Android APK"
23:37:05: Elapsed time: 00:38.

Answer 1

Looking at the source of androiddeployqt, an exit code of 15 is CannotSignPackage, so something goes wrong with signing. In addition, it could be that the META-INF warnings are related to this.