Error When Printing - The Main Thread is Blocked

The printer is throwing an error occasionally while printing saying “The main thread is blocked”. The error has occurred midway through printing several times whilst using both WiFi and USB connections.

Does anyone have any ideas on how to fix this? or what this error is trying to indicate?


I got one 80% of the way through a full roll of filament in a massive print… And it wouldn’t recover to continue after due to feed issues as it had cooked the filament in the head… :frowning: This is a major bug. I too would like to know what this means.

The main thread is blocked usually means the linux computer on the printer is crashed, therefore cannot continue the print. We are trying improve the firmware and hardware to minimize the possibility of this. If you are having frequent main thread blocking issue, we can provide replacement touchscreen to resolve the issue.

Yes please - I’ve lost 3 large prints to this bug - And when you’re printing a 400G TPU print, that means an entire roll of TPU lost every time it happens :frowning: Can you send me a PM with a link ? Or tell me what I need to do to get it?

Thanks Jason

Umm, Hang on a second - Do you mean “Replacement Touchscreen Firmware” or “Replacement Touchscreen” ?

I mean provide a new linux board with the screen.
please contact

Hi Jason,

I’ve contacted Tiertime support, but the ticket seems stuck - It’s request 22499

What do I need to do to progress the ticket?

They’ve sent me an email asking me to type a reply above the line, but they didn’t actually ask a question to respond to in the ticket.


Hi Jason,

I’m seeing other kinds of errors - wondering if they are related - Just did a short print, and got

3103.3103.3103.2.2 Error: Getting printer results timeout

Sometimes errors like that are cleared by opening and closing the main door, but not always.

And the touch panel was locked up… I’ve been getting these kinds of issues since new, but was wondering if they are related to the touch panel problem at all?


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I’ve had the main Thread blocked issues 3 times now too.
I’ve only seen this since upgrading to 1.5.10 touchscreen firmware. When it fails there’s no touchscreen response and I need to power cycle the machine. It also keep the head and bed hot so melts a hole through the print so there’s no chance of recovery.

@Jason-TT How do I fix this?

update the touchscreen firmware to latest and use the reset SD card function should help reduce main thread blocking error.

Hi Jason,

Did you ever work out if it was heat from the bed that was contributing to the screen failure? I recall someone was working on a test for that.

The new board fixed my problem entirely, so I never went back to looking.

Thanks again.

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Its mainly the resource allocation issue of an embedded system. New firmware, with codes optimized, use less system resource to perform the same function. We also increased hardware spec of the linux board in later batches, therefore you feel more responsive with the new board.

I had already 5 times the problem with “main thread is bocked”. … also after updating the firmware.
Tiertime support is not answering.
Does anyone have an alternative solution??