i have a trial key and i am working on ios with the swift.
I have the latest wikitude SDK.
When application is opened, i have described a constant as -> let wikitudeSDK: WTWikitudeNativeSDK! = nil
So, when view did load -> self.wikitudeSDK.setLicenseKey("My Key")
But application goes to crash and say that "fatal error: unexpectedly found nil while unwrapping an Optional value".
I wonder that what the problem is.
The issue you're facing is that you've declared the `wikitudeSDK` variable but did not initialize it (`= nil`).
Typically, you initialize the wikitude SDK in your view controller, once it has loaded all its views.
You should change the `let wikitudeSDK` into`var wikitudeSDK` and in your viewcontroller's `viewDidLoad` initialize it:
self.wikitudeSDK = WTWikitudeNativeSDK(renderingConfiguration: ... , delegate: self)
Only after initialization you can set the license key.
The native code examples should also be able to help you further out I think.