When you try to give a new name in the text trigger you should keep in mind that you are not allowed to use more than 45 characters. It is very important to give names in your text triggers because in case of disambiguation this name appears as an option.
Whenever you use a condition, you have to add at least one rule and attach a response (“action”) or you will not be able to save your changes.
The field inside a text trigger can't be empty. In case it is empty you will not be able to save the changes. Consider converting the text trigger to an event trigger if you come across this issue.
In order to attach a new file in a dialog you will have to make sure that this file is accessed through URL. In case you would like to use a photo or video you have to make sure that this file is accessed through URL. In case of carousel the title’s max length is 32 characters and the subtitle’s is 80 characters. Furthermore, you can have a maximum of 3 buttons per card and 6 cards. The Carousel’s title as well as Button’s Label and Postback are mandatory fields.
You will always have to keep in mind that when you save your changes, the changes are not visible to the end user. In order to be visible you will have to Publish it.