Update: On 28 December 2012 a new version of the Lycn client was posted to Google Play. This version solved the issue listed below.
The latest version of the Android OS is incompatible with Lync (or vice versa, depending on how you choose to look at it.) This issue is covered in a few support forums such as here and here
According to an internal dialog with Microsoft, there should be a fix out by the end of December.
On my Nexus 7, the failed login looks like the image below. (It should be noted that Lync is technically not supported on the Nexus 7, but I haven’t had any issues in the past getting it to work.) The error reported is innocuous enough. However, looking at the logs for the failed login, you see a java error. (No surprise that Java screws things up….)
Dec 18, 2012 7:54:06 PM ERROR HttpConnection: org.apache.http.conn.ConnectTimeoutException: Connect to /167.219.16.249:80 timed out
at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:121) at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144) at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164) at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119) at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360) at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555) at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487) at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465) at com.microsoft.office.lync.platform.HttpEngine.execute(HttpEngine.java:257) at com.microsoft.office.lync.platform.HttpConnection$1.run(HttpConnection.java:223) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:390) at java.util.concurrent.FutureTask.run(FutureTask.java:234) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573) at java.lang.Thread.run(Thread.java:856) Dec 18, 2012 7:54:06 PM ERROR TRANSPORT:CHttpConnection exception: org.apache.http.conn.ConnectTimeoutException Dec 18, 2012 7:54:07 PM INFO TRANSPORT:Received response of request(UcwaAutoDiscoveryRequest) with status = 0x22020005 Dec 18, 2012 7:54:07 PM INFO TRANSPORT:Sending event to main thread for request(0x62d1af48)Now I’ve never looked at the logs for a successful connection so the error above might be normal. But I doubt it. My absolute wild guess is that Microsoft needs to update a library or two they are using and the problem should be a fairly straightforward fix.