Error: Request failed: forbidden (403)



Hi there, I’m doing a simple iOS app with Xcode 6.4 & Objective-C.
I’m trying to display a single and specific user timeline only. and I’m using Fabric for this. at the beginning it was working.
But now it is NOT and keep show me this error “error: Request failed: forbidden (403)”.

Could someone help me to fix it ?? I just want to display the timeline as gust. no login required.