Facebook for Android SSL Problem

My app is having trouble connecting to Facebook in Android. I can connect properly on iOS, but under certain circumstances on Android, I see this error in Logcat:

 javax.net.ssl.SSLHandshakeException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.

The strange thing is that problem seems to be dependent on the workstation that builds the APK. If I build an APK in Unity on workstation A, Facebook will work properly. However, if I try to perform the build on workstation B, the app won't be able to connect to Facebook and will display the error above. Workstation B can create working builds for iOS that connect to FB without issue.

I have verified that both of these workstations have the same Unity settings. This includes:

• Inspector Facebook Settings

  • FB.Init() parameters

  • Android Build Facebook Settings

  • Facebook SDK version

• Player Settings

  • Android Bundle Identifier

I have also verified that the keyhashes appearing in the Logcat output have been added to the Android section of my Facebook App Settings page (one for each of the workstations).

I have also compared the AndroidManifest.xml in a "good" APK to the AndroidManifest.xml from a "bad" APK. They appear to be identical, along with the rest of the APK contents (more or less).

I am wondering if anyone can offer an explanation as to what else could be causing this discrepancy.

Thanks