Unknown survey command:

Dear all

Hope you are doing well

Currently I am experiencing a little problem in designing my survey. 

When I compile the survey, a compiler error message appears indicating: "Unknown survey command:"

So if I understood correctly the message, I may have made a typo, typing ":" without any command before (such as l, t or q). 

Thus I searched for all ":" written in the code and found no error. 

If I do not solve that issue, psytoolkit refuse to change the survey status to online mode. 
Can anyone help me?

Thanks in advance

Best 
J