Checking for errors in browsers

Published 28 Sep, 2017
548 words
~2-4 mins

By default browsers don't display any error messages when things go wrong. This is so your experience browsing the web is smooth and not interrupted with lots of annoying error messages. However, if something goes wrong with your Construct game, you won't see any error message at first. This can make it difficult to work out what has gone wrong.

To see error messages, you first have to open the browser's Developer Tools and view the console. The console is basically a log of messages and it will list any errors that occurred. These error messages are very useful to add to bug reports! It's also a good idea to check for errors after publishing your game to ensure it is working properly. If something is going wrong, it's also a good place to check in case it lists an error message that wasn't displayed anywhere else.

To open developer tools in each browser:

  • Google Chrome: press Ctrl + Shift + J to open Chrome's developer tools.
  • Firefox: press Ctrl + Shift + K to open Firefox's developer tools.
  • Opera: press Ctrl + Shift + I to open Opera's developer tools, which are based on Chrome's.
  • Internet Explorer or Edge: press F12 to open developer tools. Note that rather annoyingly IE and Edge won't show any errors from before you pressed F12, so it's likely you'll have to press F12 then refresh the page to see all messages. Other browsers are better and show error messages from before you opened the error console, so you don't need to refresh the page.
  • Safari: Press + + I to open Safari's developer tools.

In each browser's developer tools, usually the Console (message list) is the default view. If not, check for a tab that says Console and click on it.

Common errors

Blank screen when running project

Something has gone wrong while loading - use the shortcuts above to find any error message. You might want to post a bug report including the error message.

Game freezes half way through

Something has gone wrong during the game - use the shortcuts above to find any error message. You might want to post a bug report including the error message.

Game works in preview but not after exporting

This is usually caused by broken third-party plugins and behaviors which do not work with the minifier. The error message will probably include random characters like is undefined. Try removing third party plugins or behaviors. You should report the problem to the plugin or behavior developer, since Scirra cannot fix it. If you are not using any third party plugins or behaviors at all, you should post a bug report. As a temporary work-around, you can disable minifying script on export, but please report the bug so it can be fixed.

No audio plays, or sound files come up as '404 not found'

Make sure you've set up all the right MIME types on your server to ensure audio playback works correctly.

Some other files come up as 404 not found

Did you upload the entire project and all its files and folders? You might have forgot to upload everything. You might also want to double-check your server has the right MIME types set up.

Share this Tutorial

Make games in your browser

You may use this tutorial for any purpose (even commercial) if you properly attribute it. Click here for more information.