Stuck on Error Code 090 on Meowbit

Hi! I was trying to upload my game to the Meowbit and it hit some error and now the Meowbit is stuck on a frowny face and error code 090. I can’t find any documentation on how to re-flash the Meowbit or how to get out of this error. Does anyone have any tips or links to docs that I can use to be able to be able to get the Meowbit out of this state?


If you disconnect and reconnect the device does it display 090 or the bootloader screen with meowbit logo?

Are you on mac or pc?

Actually given that it has battery try to turn it off and on while connected to a computer.

Hi @mmoskal,

I am on a Mac (running Mojave). I was trying to deploy my makecode game using Chrome. Initially it worked fine, the Meowbit was detected but after I hit download, the Meowbit screen changed to sad face and 090. I have tried disconnecting and reconnecting to all ports on my laptop, turned power off and on while connected and disconnected to the laptop and it still shows the 090 screen and the top right LED is flashing red. I have hit the reset key, when I do that, the screen goes black for 1 second and goes back to the 090 error code. I also tried holding down the left arrow and Reset key, that displays a File screen for one second and then goes away and returns to the 090 screen. Currently my mac is unable to detect the device at all.

Is there any hardware key combo that I can use to reset the device? I will try again tomorrow by connecting it to my Windows device to see if the device is being detected.

Any tips, even if I can flash the system is welcome. :slight_smile:

I asked Kittenbot folks for new bootloader. Once we have this you should be able to update from your Windows machine.

Please update your bootloader:
You need go into bootloader with some os other than mac, and copy the file /meowbit/meowbit-flasher.uf2 to meowbit to finish the upgrade process~
If you have further question, please let us know, thanks!

KittenBot Team

KittenBot, does your answer apply to any 090 error message with Meowbit? If another Meowbit owner has this problem with iOS device and their Meowbit, should they follow your directions? If so, then I will post this on my MakeCode and Arcade YouTube channel and on r/MakeCode on Reddit; if not true then I will not repeat it. Thanks.

The fix applies to meowbit that does not go into bootloader mode (with meowbit logo and the drive appearing) when connected to Mac, but does go to bootloader when connected to Windows. It will fix the Mac situation.

It has nothing to do with 090, except that I suspect before Sweeky had it working with webusb and with the crash webusb doesn’t work anymore.

Thanks for all the responses! I am currently traveling and don’t have my Windows laptop on me at the moment. I’ll be back in a couple of days, I’ll try this out and post my results.

@KittenBot I had some questions about the process, after plugging in the device and copying that file over, should I be deleting any files present on the Meowbit? After copying over the file, do I need to press any button or do anything? Or simple restart the Meowbit?

Just restart meowbit after copying file and waiting a few seconds. It may actually ask you to restart on the screen.

Hi Everyone!

I wanted to share my update. Connecting to a windows machine and adding the bootloader provided by @KittenBot solved all my issues! I am able to load and run my games now. Thank you all for the help and helping me get unblocked :slight_smile:

@mmoskal Thank you for the responses! I am curious as to why connecting to my Mac and using Chrome caused the error while with Windows the experience was flawless.

Thanks again!

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macOS 10.14 takes longer to connect to (enumerate) USB devices. We had a timeout of 1s in the bootloader, where if nothing connected during that time we assume we’re running from a battery and not computer, and thus left the bootloader. The new bootloader increases that timeout to 3s (and mac takes about 2s to connect with 10.14). Windows just connects quicker.

Initially, you were able to flash from mac, since you were using webusb (which BTW works better on Mac than on Windows), but once your program started crashing Chrome was unable to connect to it so you couldn’t flash anymore, and you couldn’t reboot it into bootloader mode due to the slow USB connects in mac described above.