It looks like you're new here. If you want to get involved, click one of these buttons!
The variable 'form_title' does not exist. Tip: Use the variable inspector (Ctrl+I) to see all variables.
I see this every time when i want to start an experiment.
Does anyone know what i need to do?
i'm a noob at this.
To help you we need more information. Could you share the experiment? Have you used forms in your experiment? If so, you probably accidentally deleted the default title from a form item. If you put some characters in there, the error should disappear.