Fix

The panic "interface conversion: interface is nil, not X" occurs because you are performing a type assertion on a nil interface value, which is not the same as an interface holding a nil concrete value. You must check if the interface itself is nil before attempting the assertion, or use a two-value assertion to handle the failure gracefully.

var x interface{}
if x == nil {
    // Handle nil case
} else if v, ok := x.(YourType); ok {
    // Use v
} else {
    // Handle type mismatch
}

The "interface conversion: interface is nil, not X" error happens when you try to treat an empty box as if it contains a specific item. In Go, an empty box (nil interface) is different from a box containing an empty item (nil concrete value). You must check if the box is empty before trying to pull the item out.