This error message is normally caused by an issue where the Online Reader launch link is being altered by your web browser, making it invalid.

This mostly happens with browsers like Firefox that allow you to install extensions / plugins and it is this extension / plugin that is causing the issue.

As a temporary measure you can try a different web browser. This will give you access to your ebook in the meantime while you find the source of the issue.

Please try deactivating all extensions and plugins in the browser. Then retry. If you are able to open your ebook in the Online Reader then try activating just one of your extensions or plugins and retry. Repeat this process until the Online Reader does not open again. When that happens the extension or plugin you just reactivated is the likely culprit (although there could be more than one).

Then please complete our support form to submit a ticket to our customer support. Please supply the following information:

• What web browser you are using and it's version number
• A screenshot showing the error message that also includes the URL in the address bar
• Also copy the URL in the address bar and paste it in your message
• The name of the extensions / plugins that you have identified as causing the issue, or failing that, a list of all your extensions / plugins

We can then investigate and resolve the issue.