Library already initialized
A -1074 error means that NalpLibOpen() has been called more than once. NalpLibOpen() should be called once from the main thread and NOT called again until/unless NalpLibClose() has been called. A repeated call into NalpLibOpen() is mostly harmless, however, as the library protects itself.
Solution
NalpLibOpen() should be called once from the main thread and NOT called again until/unless NalpLibClose() has been called.