"It looks like you are using a browser plugin to modify Toodledo's look or behavior. This is ok, but it may not be fully compatible with our website. If things function incorrectly, please disable the plugin in your browser. If things look ok, you can dismiss this warning."
But... I fully understand your intentions. You want your users to know some plugin might have access to their tasks or at minimum causing misbehavior.
Please update the Warning to give more information about what plugins are causing the issue and allow us to trust those plugins separately, making the warning disappear. Telling us to just ignore it is not a very good option.
It was Adblock causing the issue. I disabled it for toodledo.com and the warning disappeared. But still would like the warning updated to include more information. It would have saved me a lot of time and frustration.
Unfortunately, there is no way for us to know which browser plugin is causing the complaint. Plugins that are unrelated to Toodledo can also cause this complaint. The best option is to search through your plugins and see if you can find the one causing it. Sorry for the inconvenience.