Thanks for reaching out and I'm sorry to hear that you're having an issue casting on your Chromecast. Let's sort this out.
A few questions: What is the make and model of the device you're using for casting a tab? Is this working before? For the issue with the Dailymotion app, is this only happening when casting from this app or across all apps?
Give these steps a try:
Just checking in to make sure that you've seen my response. Please let me know if you have other questions or concerns as I will be locking this in 24 hours if I won't hear back from you again. Feel free to start a new thread and we'll be happy to help.