Call-time pass-by-reference has been deprecated
 

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Those are warnings, and can be disregarded. If you see those on a page accessed through a web browser, then your PHP configuration's error level setting is not appropriate.

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Call time pass-by-ref is when you call a function, and in front of an (variable) argument you add "&", passing the variable by reference. As the error suggests, you can fix this by removing the "&", and changing the function declaration to automatically fetch the argument by reference.

Alternatively, enable call time pass-by-reference as mentioned in the error.

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