For support in English, ask for help on the Omega Discord.

Black screen and red LED

Your calculator is in Recovery mode, it’s waiting to receive a firmware, so it’s unlocked. If you update from Numworks’ website, your calculator will be locked

Choose a CFW to install on your calculator. (If you want to install Epsilon without locking your calculator, install first a compatible CFW while in recovery mode, then install Epsilon while NOT in recovery mode)

Black screen, yellow cable, and

This is Numworks’ bootloader. It shows up when the calculator is locked and you started the Recovery mode by holding 6 and pressing reset, or when the calculator couldn’t start.

If you want to unlock your calculator, don’t go to the website, but follow the guide from Installing Epsilon 18.2.0.

Black screen, nothing else

There are 4 possible reasons:

  • Your calculator is in sleep mode, press the power button to turn it back on.
  • Your calculator may have any wierd bug, try pressign the reset button on the back.
  • Your calculator may be discharged, try letting it charge a few minutes.
  • The battery is disconnected, you may need to open your calculator to plug it back in.

If this doesn’t solve the problem, contact Numworks.

Huge battery consumption

There are 2 possible reasons:

  • You have enabled the clock in the settings, some custom firmwares include it. The clock consumes a lot of battery and it’s highly recommended to disable it.
  • Your calculator keeps the led green. This is a hardware issue that tricks the calculator into thinking it’s constantly charging and so fully charged while it’s not the case. You should contact Numworks to replace your calculator

Calculator not detected

There can be multiple reasons: You may not be clicking the right button, or the driver or config file isn’t installed on Windows or Linux.

Make sure you if you are in Recovery mode you click on the “Recovery” button and not on “Detect Calculator”.

To get the driver, open the Rescue page on Numworks’ website and it will give it and tell you how to install it. Don’t plug in your calculator to make sure you don’t lock it

If you are using Linux, it may still not be detected. It can happen if your web browser is installed as a flatpak or a snap.

If you use flatpak, you will need to install Flatseal, select your web browser, and add /run/udev in the “Other files” into the “Filesystem” category.

You can also run this command: flatpak override --user --filesystem=/run/udev [Application ID] (Replace [Application ID] with your web browser’s ID, try to run flatpak list to find it)

If you use snap, run this command: snap connect [Application ID]:raw-usb (Replace [Application ID] with your web browser’s ID, try to run snap list to find it)

Don’t forget that you may need to restart your web browser if you unplug and replug the calculator.

Recovery mode (Black Screen + Red Led), calculator not recognized

Your calculator looks like it’s in recovery mode but it isn’t.

Hold 6 and click reset to start it in recovery mode, it will look the same but this time, it will be recognized.

“CommandName is not defined”

You are trying to do something with the calculator but the calculator isn’t in the right mode, like trying to install apps with the calculator in Recovery Mode or on n0100.

Try to use the right mode, for external apps just run it in normal mode.

“Unable to claim interface”

This error is displayed when you try to connect your calculator but it’s already used by another tab or software. It usually happens when you try to install external apps but the tab you used to install your custom firmware is still open.

This can easily be fixed if you close the tab or software already connected to it. Only one tab (or software) at a time can establish the connection to the calculator.

“Could not detect the calculator model” / “N????”

This means your calculator is protected against CFM installation. If you want to install CFW, you need to unlock it.

Follow this guide to unlock it.

“Memory is corrupted” when adding python scripts

It can happen when the custom bootloader is too old. To update it : go to your custom firmware’s website, put the calculator in recovery mode (holding 6 and clicking reset on the calculator’s back), connect the calculator to the computer, then select “recovery” on custom firmware’s website.

Screen and led blinking

You are trying to run Epsilon 19 with an old custom bootloader.

Update the bootloader : go to your custom firmware’s website, put the calculator in recovery mode (holding 6 and clicking reset on the calculator’s back), connect the calculator to the computer, then select “recovery” on custom firmware’s website.

Installation takes infinite amout of time

This can happen on Omega’s website and on Numworks’ website. Unless your calculator is locked, the firmware is already installed but the website is trying to boot the calculator and it can’t.

Just click reset on the calculator and it should be fixed

“Address 0x90000000 outside of memory map”

You are trying to flash the external partition but the calculator is not in the right mode. This can’t work.

You need to flash while in Numworks’ bootloader, the custom bootloader or recovery mode flasher (the screen saying “Recovery mode” when installing Omega in Recovery mode)

Calculator restarts when trying to install custom firmware

Your calculator is running Epsilon 19 or higher, it can happen when the calculator is locked or when you are running it from custom bootloader.

Just restart the calculator in bootloader or any other firmware that isn’t Epsilon 19 or higher

“ControlTransferIn” / “ControlTransferOut”

Something interrupted the connection with the calculator.

Make sure you are in the right mode and no other app or tab is using the calculator.


You may not be using the right WebDFU, make sure you are using TI-Planet’s WebDFU

“Access Denied” when trying to connect the calculator in Recovery mode

This can happen on Windows and Linux:

  • On Linux it means you haven’t installed the config file, Numworks’ update page will give it to you.
  • On Windows it means you are in recovery mode and the wrong driver is selected, there are a few steps you can follow to fix this
    1. If it’s not installed, install the driver from Numworks’ update page
    2. Open Device manager, press Win+R, type devmgmt.msc, and press enter
    3. Search for a device with STM in the name
    4. Right click on it, and press “Update Driver”
    5. Dont search automatically for drivers, Search for it manually. Then decide to choose in a list.
    6. Select the Numworks driver, then press next
    7. The driver should be correctly installed, you can now connect in recovery mode and it should work.

Crash when starting Upsilon

Upsilon tends to crash when you start it and the calculator is connected to a PC. Disconnect it before starting.

In Dualboot, KhiCAS makes the calculator crash

KhiCAS is a heavy app and dual-booting with this app installed is not possible.

You may have installed KhiCAS, then Epsilon, which erased a part of KhiCAS, preventing it from starting.

If you want to use KhiCAS, you will need to reinstall it.

Is you error not listed ? The provided solution didn’t fix your problem ? Don’t hesitate to ask on the Omega Discord