See also the list of Known Issues.

General Issues

• I have problems deploying/launching the application in Qt Creator.
• I have problems deploying/launching a Qt or Qt Quick example application.
• I have problems launching or running applications on hardware after updating the SDK.
• Terminating application. Error running process: Process crashed.
• Mouse or touch input doesn't work.
• Application stops with 'EGLFS: OpenGL windows cannot be mixed with others.'
• I can't edit the contents of appcontroller.conf on the device.
• How to enable C++17 features?
• How can I run a script on my target device when I select the run button in Qt Creator?
• How can I set a remote deploy directory for my application?
• I get an error: "EGL Error : Could not create the EGL surface: error = 0x3003".
• Boot to Qt is set to automatically start the application but the application isn't showing up.

Connectivity Issues

• I can't connect to my embedded target device via USB.
• What are the user and password to access my embedded Linux device?
• I get an error: "Connection error: Timeout waiting for reply from server."
• I can't connect to my embedded target device via Ethernet.

General Issues

I have problems deploying/launching the application in Qt Creator.

Check that the device is properly connected to the development host via USB or Ethernet (depending on the device). See Connectivity Issues.

I have problems deploying/launching a Qt or Qt Quick example application.

Because of a technical peculiarity in qmake, it is not possible to get correct deployment setup for any application that is placed inside a Qt source code tree.

The workaround is to copy the example sources to a location outside the Qt source tree, and open this copy of the example application instead.

I have problems launching or running applications on hardware after updating the SDK.

Remember to repeat the process of updating also your device with the latest version of Boot to Qt Software Stack. See the Boot to Qt Software Stack quick start guide for your target device in the Quick Start Guides section.

Terminating application. Error running process: Process crashed.

When terminating an application from Qt Creator, you might see the message Terminating application. Error running process: Process crashed. This is normal and does not indicate a problem in your code; a SIGTERM signal is sent to the application, and Qt interprets it as a crash.

Mouse or touch input doesn't work.

See Customization.

Application stops with 'EGLFS: OpenGL windows cannot be mixed with others.'

OpenGL and Qt Quick 2 applications can only have one fullscreen window existing at a time. Trying to create another OpenGL window, or trying to mix an OpenGL window with a raster one will display the above message and abort the application.

I can't edit the contents of appcontroller.conf on the device.

The file system where this file is located might be mounted as read-only.

See Customization.

How to enable C++17 features?

To enable C++17 features in the compiler, add CONFIG += c++17 to the .pro file.

How can I run a script on my target device when I select the run button in Qt Creator?

You can add a custom deploy step Custom Remote Command as instructed in Deploying Applications to Generic Remote Linux Devices.

When you add the custom remote command, remember to include a full path to your script in the remote command. Also, ensure that your script has enough execute permissions.

How can I set a remote deploy directory for my application?

The remote deploy directory depends on the value of qmake INSTALLS variable that you set in your project's .pro or .pri file.

In order to deploy to /my/installation/directory, add the following code to your .pro file:

target.path = /my/installation/directory
INSTALLS += target

If you use .pri file, you can define as follows:

target.path = /opt/$${TARGET}/bin

I get an error: "EGL Error: Could not create the EGL surface: error = 0x3003".

The error might appear if Qt cannot create a new surface due to the target device screen being used by some other application. When you deploy an application with Qt Creator, you should not see this error as the appcontroller ensures that the application is deployed properly. Thus in case of an EGL error, you should consider if you can use Qt Creator for deploying your application.

If you do not use Qt Creator for deploying applications, you must ensure yourself that the target device screen is not used by any other application. For example, Get Started with Boot to Qt must not be running on the device. You can also check if updating the EGLFS related environment variables helps. For more information, see EGLFS.

Boot to Qt is set to automatically start the application but the application isn't showing up.

Carry out the following steps:

1. In a terminal, log into the target device via SSH.
2. Run the following commands:

   systemctl status qtlauncher
   systemctl status b2qt

   The resulting logs might help to identify the issue.

Connectivity Issues

I can't connect to my embedded target device via USB.

• Linux

  Check that you have set an udev rule as instructed in Setting up USB Access to Embedded Devices.

• Windows

  You can check whether a driver is already installed when a device is attached via the Device Manager. If you haven't installed any driver there should be an USB Function Filesystem under Other devices. If this is the case, install the USB driver with the following steps:

  1. Open Other devices > USB Function Filesystem.
  2. Switch to the Driver tab and select Update Driver.
  3. Do not let Windows search automatically for an updated driver, but select Browse My Computer for driver software.
  4. Select Let me pick from a list of device drivers on my computer.
  5. Open Have Disk...
  6. Install the driver that is located in <SDK>\\Tools\\qdb\\usb_drivers\\qdb_driver\\qdb_device.inf.
• Linux/Windows/macOS

  If all the steps above have been done and USB Ethernet has been configured according to Setting Up USB Ethernet on Target Device you might need to take logs from the target device to report a new bug or contact Qt support.

  You should include a QDB log file to your support request. You will find the log file from %APPDATA%\qdb\qdb.log on Windows, and from ~/.local/share/qdb/qdb.log on Linux, and from ~/.Library/Application Support/qdb/qdb.log on macOS.

What are the user and password to access my embedded Linux device?

Embedded Linux devices can be accessed using user root and an empty password.

I get an error: "Connection error: Timeout waiting for reply from server."

The error might appear in Qt Creator even if the target device is shown as Ready to use in green.

To solve the issue:

• Ensure that your host computer is configured to fetch an IP by DHCP for the newly discovered interfaces. Alternatively, you can configure it manually to the matching subnet.
• Use 172.16.58.2/30 as a configuration if it's the only Boot to Qt device connected to the host and if the IP is not already part of some other network on the host.

I can't connect to my embedded target device via Ethernet.

Qt Creator must know the IP address of the target device. If the Get Started with Boot to Qt does not show the IP address of the target device when you turn on your device, you need to use other means to find out the IP address.

Alternative ways to find out the IP address of your device:

• Use the ip address Linux command to find the IP address via the USB debug terminal on the target device.
• Boot to Qt Software Stack uses DHCP, so you can look for its IP address at your network router.
• Reboot your target device and listen to the DHCP requests on your local network, for example, on Linux with the sudo tcpdump -i <ethernet-interface> port 67 or port 68 -e -n -vv command.