Add section for troubleshooting. Closes #3622

docs/Troubleshooting.md

@@ -7,7 +7,7 @@ permalink: docs/troubleshooting.html
 ---
 
 ## Cmd-R does not reload the simulator
-Enable iOS simulator's "Connect hardware keyboard" from menu Hardware > Keyboard menu. 
+Enable iOS simulator's "Connect hardware keyboard" from menu Hardware > Keyboard menu.
 
 ![Keyboard Menu](https://cloud.githubusercontent.com/assets/1388454/6863127/03837824-d409-11e4-9251-e05bd31d978f.png)
 
@@ -85,3 +85,11 @@ If you are adding React manually, make sure you have included all the relevant d
 In the project's build settings, `User Search Header Paths` and `Header Search Paths` are two configs that specify where Xcode should look for `#import` header files specified in the code. For Pods, CocoaPods uses a default array of specific folders to look in. Verify that this particular config is not overwritten, and that none of the folders configured are too large. If one of the folders is a large folder, Xcode will attempt to recursively search the entire directory and throw above error at some point.
 
 To revert the `User Search Header Paths` and `Header Search Paths` build settings to their defaults set by CocoaPods - select the entry in the Build Settings panel, and hit delete. It will remove the custom override and return to the CocoaPod defaults.
+
+## Unable to connect to development server
+
+##### iOS
+Ensure that you are on the same WiFi network as your computer. If you're using a cell data plan, your phone can't access your computer's local IP address.
+
+##### Android
+You need to run `adb reverse tcp:8081 tcp:8081` to forward requests from the device to your computer. This works only on Android 5.0 and newer.