Common errors and solutions

Our development team are constantly working to improve the user experience for everyone on Sumdog. But sometimes that can throw up teething problems. 


On this page you can find details about common (and not-so-common) errors that might impact your Sumdog experience.




Problem: Stuck on an orange loading screen

This image appears if the games have not fully downloaded during the Warm Up. Don’t worry, the dog won’t be stuck forever! 

The Warm Up provides some quickfire questions to keep students engaged during the game loading process. If the Warm Up is completed before the games are downloaded, you might see this screen. 

The Warm Up usually takes about a minute to complete. If games haven’t fully downloaded during that time, they will continue to complete downloading when you click on the games to get started. 



This is normally fixed by waiting briefly for the games to load. Don’t click back or refresh if you see this image.


You should also avoid clicking back or refresh during the Warm Up session itself, as that will restart the game download and result in a further delay.


This screen should normally only last a minute or two, depending on your internet speed. If you notice that it is taking longer, here are some key points worth checking:

  • Check your internet isn’t running slowly, or being slowed down by other downloads. This can impact how quickly Sumdog games download during the Warm Up. 
  • Try moving your device closer to the router or wireless modem. This can sometimes help boost the connection and speed of downloads.
  • Try using a wired connection instead of wireless if you’re using a computer to log on. This can often provide a more stable connection.
  • Try logging on with a different device to see if this can help.
  • If you have a larger group of students starting Sumdog at the same time, try having them log on in groups. This means downloading games won’t take place simultaneously for a large group, reducing the demand on your internet connection.


If you have carried out all these steps and the problem persists, please feel free to get in touch with us at and our team can investigate further


It would be helpful if you could make a note of how long the screen was stuck in loading, and the rough date and time when it happened. A note of your browser version and username of the affected account would also help us in investigating the problem.


Problem: Sumdog is running slowly message

This message occurs if your internet is running slowly. There are several reasons that this might be the case: 

  • Wireless connection to the internet may have been lost
  • Your device has moved too far from the router or modem
  • Multiple devices or users are operating on the same network
  • Large downloads are occuring on the network
  • Overall internet speed is poor
  • Your internet service provider (ISP) is encountering difficulties
  • Snails have taken over your modem


There are a number of troubleshooting steps you can take to tackle slow internet speed.

  • Check your internet connection either on your computer, or by checking the router or modem itself
  • Run an internet speed test here to confirm the download speed you’re receiving
  • Try connecting to a wired internet connection instead of wireless
  • Move your device closer to the internet router or modem
  • Ensure there are no large downloads or demanding video streaming on the network as this can put a strain on download speeds
  • Try having your students log on in small groups instead of all at once
  • Turn the router or modem off for a minute, then switch it back on
  • Turn the network connection on your device off, and then on again to see if this establishes a better connection
  • If you are using a device with Wi-Fi, try turning that off and using the mobile 4G data network instead to see if it may be an issue with the Wi-Fi (data charges may apply)


It’s possible that you might need to log out of the account, wait a few minutes, and log back in once the connection has improved. 


Problem: Sorry, Sumdog won’t work on this device message

Sumdog games all operate using HTML 5, and require WebGL to be supported and enabled on a web browser. This message will appear if your browser does not support WebGL.

Unfortunately, WebGL is not supported on any version of Internet Explorer, but will run on the latest versions of Microsoft Edge, Mozilla Firefox, Google Chrome, and Safari for Apple devices.


Your first step is to ensure you’re running a supported web browser version. You can find a list of all supported browsers and devices for running Sumdog here.


You can run a Sumdog browser test here to check which browser you’re operating on.


If you are operating on a supported browser, your next step is to check to ensure that WebGL is supported on your device. Run a check here to check if WebGL is operating.


If you are accessing Sumdog via a computer or device with an older graphics card that predates 2012, it may be that WebGL is not supported. In this case the problem is unfortunately a hardware issue, and can only be solved by updating to a newer device or replacing your older graphics card. 


If you are using an Apple Mac computer, you may encounter this message when attempting to log onto Sumdog using Google Chrome. Chrome may not support Mac hardware in running Sumdog. If this is the case, we advise you to attempt to log on to Sumdog using Safari browser instead.


Other issues?

If the issue you’re encountering is not listed on this page, please do get in touch so our team can look into the problem and see what we can do to help. You can email us at with any such problems.


When reporting a problem, please include the following details:

  • A screenshot or image of the error you’re receiving
  • A note of the date and time the issue occurred
  • Confirmation of the device or computer type you’re using
  • A note of the browser type and version if possible (if on a computer)
  • Confirmation of Sumdog app version (if on a tablet)
  • Name and username of the affected account or student

These details are important to ensure we can investigate any problems fully. 


Any questions? Email

Still stuck? ... Contact us