Android Question B4A 9.50 Cannot connect to Emulator - Designer9.apk install failed.

[mcqueccu]

Hi, I cannot connect to any emulator on my PC with the new version. Older versions worked succesfully. I kept getting INSTALL_PARSE_FAILED_NO_CERTIFICATE. I restarted my adb several times

 

[Jack Cole]

You might double check to see if your private sign key is set up. Click Tools, Private Sign Key.

What happens when you try to install to a device connected via USB?

 

[Erel]

It is not related to the developer signing key.

I'm unable to reproduce it. Are you using B4A trial version? Have you tried to create a new AVD? Which version of Android are you using?

 

[mcqueccu]

Am using Debug key.

I tried it on real device, it worked with Bridge and USB Debugging.

Real Device is Android 7
Emulator is android 4.4

 

[Erel]

Try to create a new AVD.

 

[mcqueccu]

Tried with 2 AVDS
Android 7 AVD - Worked fine
Android 4.4 AVD - Error

EDIT: Tried with Live Device Samsung Running Android 5.1 - Worked Fine

Did some reading on this Stackoverflow Link

Spoiler: stackoverflow

Android 7.0 introduces a new signature scheme, V2.
The V2 scheme signs the entire APK rather than just the JAR, as is done in the V1 scheme. If you sign with only V2, and attempt to install on a pre-7.0 target, you'll get this error since the JARs themselves are not signed and the pre-7.0 PackageManager cannot detect the presence of the V2 APK signature.

To be compatible with all target systems, make sure the APK is signed with both schemes by checking both signature version boxes in Android Studio's Generate Signed APK dialog as shown here:

Also From https://source.android.com/security/apksigning/index.html

Spoiler: android source

APK signing schemes

Android supports three application signing schemes:

• v1 scheme: based on JAR signing
• v2 scheme: APK Signature Scheme v2, which was introduced in Android 7.0.
• v3 scheme: APK Signature Scheme v3, which was introduced in Android 9.

For maximum compatibility, sign applications with all schemes, first with v1, then v2, and then v3. Android 7.0+ and newer devices install apps signed with v2+ schemes more quickly than those signed only with v1 scheme. Older Android platforms ignore v2+ signatures and thus need apps to contain v1 signatures.

 

[Erel]

The attached APK should work with all devices. Copy it to the installation folder.

 

[mcqueccu]

Designer can now connect to the emulators. Working fine now.

One Final Question based on post #6, Does B4A Sign apks with all signing Schemes available thats the V1, V2 and V3?

 

[Erel]

The issue was not related to the signing version. It was related to the signature being SHA256 instead of SHA1.

B4A signs with V1 scheme.

 

[Jorge M A]

The attached APK should work with all devices.

Sorry @Erel, this is a general update for everyone?

Autoanswer:

I had to update due message:

 

[Erel]

Not for now. You should download the updated APK and copy it to the installation folder.