I think it will be impossible to help you without seeing your code, but I would start with some code that will document what happens when this error occurs (what path you're using to call the VI and so on). That will make it much easier for you to troubleshoot.
Additionally, you can try searching this site for the error. If you go to the top of the page and put 1124 in the search box, you will get several results (like
this, for example).
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