Hi @Steven.H.A sorry to hear it. Without knowing the method you are using to include SQLCipher in your project I can’t offer much help. Please have a look at the following resource, and ensure that the sqlite3.h file for your build of SQLCipher is in your project structure and available through the Header Search Paths setting:
That article summarizes the various ways this can happen and offers several work-arounds and things to check.