Hmmmmmmm......it may be that your installation of Opera and/or any widget/add on/plug in that you may have is corrupt.
Dragonfly is a developer and diagnostic tool built into Opera .......quote from Opera help pages ......."Opera Dragonfly is a tool for developing and debugging local and remote webpages. It includes a DOM view of webpages and highlighting of elements. You can step through your JavaScript code, and quickly inspect changes to your CSS styles. You can debug your extensions and widgets, and study your application's impact on network resources."
To close Dragonfly.....again quote from Opera help....."To close Opera Dragonfly, take one of the following steps:
Click the close icon ("X") on the upper right side of the Opera Dragonfly window.
From the main menu, uncheck Page > Developer Tools > Opera Dragonfly.
Use the keyboard shortcut Ctrl + Shift + I.
When the Opera Dragonfly window has focus, use the keyboard shortcut Ctrl + W, as with any other tab."
Dragonfly should not open by itself....only when you ask it to.......the "errors" that it is reporting are scripting errors on the web page you are viewing and you cannot cure them.
Could I suggest that you download a fresh Opera from the likes of Filehippo.......uninstall the present one and re-install. Don't worry about your prefs.......they are held in a directory seperate from the actual program and will not be lost by uninstalling.
When reinstalling, look carefully at the options as you install........there may be the opportunity then to not invoke Unite.
ps.......you did not attach your piccy..