Thanks @robski. I tried the latest 2.3.1 , the oldest 2.0.3 and more.
I just tried again,
Now it works with 2.0.3
and up to 2.2.6

2.2.7 and newer ones i get this weird black screen with some elements showing up when pressing buttons, as in the screenshot above.
in some cases, i could not burn a lower version until i used the erase option before burning.

EDIT:
now i realized with 2.2.7 and up to 2.3.1 although the screen is black on bootup, it connects to the cloud and i can send programs to it.

So, form 2.2.7 on just the UI broken.

I use M5Burner 202505131800
Flashing fails with different symptoms:

Maybe a year ago or more i had tried, and it always finisthed after an abnormally fast flash-progress (2-3sec.) with a success message, but then never showed anything on display, looked like dead.
I could always return to UIFlow 1 Versions.

Now i tried again, and after a few fails it worked one time, i saw the new UI. But i could not connect.
So i flashed again with an older Version, 2.3.0 i think.
But now the screen was black again. Pushing buttons plays the different pitch beeps, and the screen shows some of the elements:

I have two of the sticks, same issue with both...
Again, i can return to UIFlow1, but no luck with UIFlow2.
I tried multiple erases before flashing too, no change.

Is this a known issue? Any ideas to fix it?

I miss some things in the documentation (https://docs.m5stack.com/en/hat/hat-joyc):

• What is the switch doing?
  I can see that the led's are turned on and off, does it have other effects?
• What does the Battery do?
  Does it charge the StickC
• Is there a Schematic, like it can be found for StickC Plus etc. ?
  This would most probably answer the above question...

@ajb2k3 Thanks. Yes, i am aware of StickC/plus/2plus, should be on the right one, will check again.

As for loading a script from device, i found the solution. It behaves just like what i was expecting:

What's not entirely clear to me yet is how scripts are saved on the device. I mean, will it be every new project name? Easy to test, but i did not yet...

If anybody from M5Stack is reading here:
The Fact that i did not find the solution and then 3 People answering without finding the correct answer is a strong indicator that the UI is not self-explanatory enough.
It's not logical that there's a LOAD Icon (load from PC), with the LOAD (from device) is hidden in a different icon's submenu.
I think the LOAD Button should lead to an options-dialogue "-from host / -fromdevice"

Thanks.

@kuriko, i did not get UiFlow2 to work yet on my StickCPlus (With Firmware 1.13.8). Trying the UiFlow2 Firmware, i only get a blank screen.
But i see i can connect to my Stick in UIFlow1.0 too.
I get to the REPL interface, with os.getcwd() i can see that i am in /flash.
Yes. main.py is what i was looking for.
But i have some questions:
If i use the APPList from the boot menu, some .py scripts are listed, temp, main, test and MyCustomCode.py
in /flash, there is main and temp.
Then, there's a DIR named apps. In it, there's again main.py and MyCustomCode.py.
What's the logic here, how did all the scripts end up where they are?
I guess the "current" one is always copied to main.py, but what's with temp.py and test.py? I am not aware of ever using these names.
Maybe there's a help doc. on the topic that i should read?

@Cognitive5525, with Thonny, i don't see how to get to the file i need. I guess i would need to connect to my Stick first, but don't see anything about it in the menus...

I have a StickC Plus with a working program on it, but i lost the source file.
Is there a way to read a blockly/python script from a Core device?

1. I assume the python source code is on the Core Device and being run through a MicroPython interpreter.
   Is that correct, or is the Soruce being compiled down to something else before it is downloaded to the Core?

2. Assuming 1. is correct, is there a way to read back the python script?
   (appart from reading it back directly from the flash chip with a programmer and extracting from there)

I miss some descriptions and/or a schematic, to understand details of JoyC:

1. Which pins from the StickC are used by the JoyC, which are available for other purposes?
   (I guess only 2 pins are used for SDA/SCL, so one should be available)

2. Also, i wonder what the Battery on JoyC does. Does it power the stick, or does it only drive the JoyC?

3. What is the switch doing?
   I can see that the led's are turned on and off, but does it also have other effects?

@m5stack could you provide Examples for the Servo?
I am mainly interested in having it in an Arduino example, but also for UiFlow.
Something that shows how the angle and pulse commands (angle is self explaining, but pulse less so).
Maybe this could be added to the existing examples?
In the Docs, i don't see much about the Claw, except the register description.

@zano

Thank you very much for reply , is there any instructions or tutorial how to compile the icon.c image array into the file and compile time , i would be thankfull .
Best Regards .
A workaround is to just copy the contents of icon.c into the main script where the include-line was.
So, overwriting the include-line with the contents of the file that was meant to be included.

I thought it would be enough to have icon.c in the same folder as the main script, but it was not fould that way for me.
Pasting into the main File is not the intended way to do it, so can anyone tell how includes are meant to work here?
I am pretty sure the path of the main script is normally working for include commands...

The two Sticks on the Board lock in place if you throttle the stick to the limit, and only jump back to zero if you help them.
Can this lock-feature be disabled somehow? Because for me, it's a Bug right now.
The obvious solution is to add some kind of mechanical stop, eg. elevate the existing led-cover, so the stick can't reach the lock position.
I need to get some spacers and longer screws for that.
But i wonder if there's another way, which i am overlooking. Something simple like removing/turning a screw/knob or so...
The shop- and doc- page don't mention the locking-feature at all, is it actually a bug, and not a feature?