Running the tutorial fails with "unicode error" - icon.ico not created?

[Cecron]

I tried to follow the BeeWare tutorial but fail to run both briefcase create and briefcase run android due to some unidentified "unicode". briefcase dev works as expected. I am running on Windows-11-10.0.26100-SP0 with Python 3.13.12 [MSC v.1944 64 bit (AMD64)].

I got the following error when running briefcase create:

>briefcase create
C:\proj\python\beeware\tutorial\.venv\Lib\site-packages\requests\__init__.py:113: RequestsDependencyWarning: urllib3 (2.6.3) or     chardet (7.0.0)/charset_normalizer (3.4.4) doesn't match a supported version!
  warnings.warn(
[helloworld] Generating application template...
Assigning helloworld an application GUID of 93bbf2ae-12d0-580c-aeb0-965dc4c04b69
Using app template: https://github.com/beeware/briefcase-windows-app-template.git, branch v0.3.26
Cloning template 'https://github.com/beeware/briefcase-windows-app-template.git'...
Using existing template (sha 963d0d61daf11344b656430d45701eab70407f60, updated Wed Dec  3 06:10:36 2025)
Log saved to C:\proj\python\beeware\tutorial\helloworld\logs\briefcase.2026_03_04-17_32_58.create.log
Traceback (most recent call last):
  File "C:\proj\python\beeware\tutorial\.venv\Lib\site-packages\binaryornot\helpers.py", line 103, in is_binary_string
    bytes_to_check.decode(encoding=detected_encoding['encoding'])
    ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: decode() argument 'encoding' must be str, not None
During handling of the above exception, another exception occurred:
.....
  File "C:\proj\python\beeware\tutorial\.venv\Lib\site-packages\binaryornot\helpers.py", line 106, in is_binary_string
    unicode(bytes_to_check, encoding=detected_encoding['encoding'])  # noqa
    ^^^^^^^
NameError: name 'unicode' is not defined

Turning on debugging, it looks like it is the file icon.ico which is the currently processed file:

DEBUG cookiecutter.generate: Processing file icon.ico
DEBUG cookiecutter.generate: Created file at             C:\proj\python\beeware\tutorial\helloworld\build\helloworld\windows\app\icon.ico
DEBUG cookiecutter.generate: Check icon.ico to see if it's a binary
Log saved to C:\Users\tim\proj\python\beeware\tutorial\helloworld\logs\briefcase.2026_03_04-19_31_56.create.log
Traceback (most recent call last):
...

A problem could be that I don't have any icon.ico file there? Adding one manually does not help since this directory seems to be removed.

No errors seen when running briefcase create android, but then the following error when running briefcase run android:

>briefcase run android
C:\proj\python\beeware\tutorial\.venv\Lib\site-packages\requests\__init__.py:113: RequestsDependencyWarning: urllib3 (2.6.3) or  chardet (7.0.0)/charset_normalizer (3.4.4) doesn't match a supported version!
  warnings.warn(
...
[helloworld] Starting app on @beePhone (running emulator) (device ID emulator-5554)
...
[helloworld] Installing app...
...
[helloworld] Following device log output (type CTRL-C to stop log)...
===========================================================================
--------- beginning of main
I/mple.helloworl: Late-enabling -Xcheck:jni
W/mple.helloworl: Unexpected CPU variant for X86 using defaults: x86_64
D/CompatibilityChangeReporter: Compat change id reported: 171979766; UID 10105; state: ENABLED
V/GraphicsEnvironment: ANGLE Developer option for 'com.example.helloworld' set to: 'default'
V/GraphicsEnvironment: Neither updatable production driver nor prerelease driver is supported.
D/NetworkSecurityConfig: Using Network Security Config from resource network_security_config debugBuild: true
D/NetworkSecurityConfig: Using Network Security Config from resource network_security_config debugBuild: true
D/libEGL  : loaded /vendor/lib64/egl/libEGL_emulation.so
D/libEGL  : loaded /vendor/lib64/egl/libGLESv1_CM_emulation.so
D/libEGL  : loaded /vendor/lib64/egl/libGLESv2_emulation.so
D/AppCompatDelegate: Checking for metadata for AppLocalesMetadataHolderService : Service not found
D/MainActivity: onCreate() start
W/mple.helloworl: Accessing hidden method Landroid/view/ViewGroup;->makeOptionalFitsSystemWindows()V (unsupported,     reflection, allowed)
D/MainActivity: Starting Python
W/mple.helloworld: type=1400 audit(0.0:12): avc: denied { read } for name="overcommit_memory" dev="proc" ino=14444 scontext=u:r:untrusted_app:s0:c105,c256,c512,c768 tcontext=u:object_r:proc_overcommit_memory:s0 tclass=file permissive=0     app=com.example.helloworld
W/native.stderr: Could not find platform independent libraries <prefix>
W/native.stderr: Could not find platform dependent libraries <exec_prefix>
W/native.stderr: Fatal Python error: Failed to import encodings module
W/native.stderr: Python runtime state: core initialized
W/native.stderr: ModuleNotFoundError: No module named 'encodings'
W/native.stderr:
W/native.stderr: Current thread 0x0000737aef5b84f8 (most recent call first):
W/native.stderr:   <no Python frame>

This seemed like a pretty straight-forward problem but I was not able to find anything useful while searching (except that unicode is supposed to be a non-issue with Python3 ;-).

[freakboy3742]

Thanks for the report. Sorry to hear you've had problems - these are all very weird issues that I haven't seen before.

The unicode errors are a bit of a red herring - the problem doesn't appear to be anything to do with unicode, but instead missing files where "None" isn't a valid unicode string.

The actual failure modes are quite distinct - but they both suggest that downloads have been corrupted. The Android failure indicates that there are significant parts of the packaged application missing; the Windows failure suggests the original template hasn't been rolled out completely.

Making matters worse, it looks like the Windows failure has occurred while trying to write the diagnostic log. It mentions a log saved to "C:\proj\python\beeware\tutorial\helloworld\logs\briefcase.2026_03_04-17_32_58.create.log" - Does that file exist (or does a replacement get created if you re-run briefcase create)? If so - can you provide it?

The next thing to check - can I get you to delete your Briefcase cache folder (C:\Users\USERNAME\AppData\Local\BeeWare\briefcase, replacing USERNAME as appropriate), and delete build, and re-run briefcase create?

If you still get the error, can I ask you to provide a zipped up copy of your project folder so I can compare to what should be happening.

[Cecron]

I tried to remove the Briefcase cache folder, but I got the same problem. Since you mentioned corrupted downloads, I recreated everything from scratch, and today I got new versions of the app templates:

[helloworld] Generating application template...
Assigning helloworld an application GUID of 93bbf2ae-12d0-580c-aeb0-965dc4c04b69
Using app template: https://github.com/beeware/briefcase-windows-app-template.git, branch v0.4.0
Cloning template 'https://github.com/beeware/briefcase-windows-app-template.git'...
Using existing template (sha 9ab013027f7257c2352da90fe5ec10e7ec6df8d8, updated Mon Feb 16 02:45:13 2026)
...
[helloworld] Generating application template...
Using app template: https://github.com/beeware/briefcase-android-gradle-template.git, branch v0.4.0
Cloning template 'https://github.com/beeware/briefcase-android-gradle-template.git'...
Using existing template (sha 4ab838cc49444665e6bf1326a5e49b444d8d87d6, updated Mon Feb 16 13:21:10 2026)

and everything worked, once I also created a new Android emulator device. I guess there is a way to delete Android emulator devices as well...

So perhaps I was downloading while a new version was released, and I ended up with a mismatch of files?

Big thanks for getting back so quickly with an answer, otherwise I would not have retried Beeware for a number of months. ;-)

[freakboy3742]

It definitely wasn't a "mid release install" problem - firstly, all the template versions etc are hard locked to the version of Briefcase being used; but secondly, I answered your question before I did the 0.4.0 release yesterday :-)

Regardless, I'm glad the problem is now resolved.