AuthorizationService is checking for an installed browser at initialization time. I'm thinking this should probably be delayed until you actually need it. It's possible the user logged in and then disabled their browser (yeah, i know), and you can't use AuthorizationService to refresh tokens, even though you don't need the browser at that point.

Caused by: java.lang.IllegalArgumentException: Service Intent must be explicit: Intent { act=android.support.customtabs.action.CustomTabsService } at android.app.ContextImpl.validateServiceIntent(ContextImpl.java:1209) at android.app.ContextImpl.bindServiceCommon(ContextImpl.java:1308) at android.app.ContextImpl.bindService(ContextImpl.java:1286) at android.content.ContextWrapper.bindService(ContextWrapper.java:604) at android.content.ContextWrapper.bindService(ContextWrapper.java:604) at android.support.customtabs.CustomTabsClient.bindCustomTabsService(CustomTabsClient.java:64) at net.openid.appauth.BrowserHandler.bindCustomTabsService(BrowserHandler.java:86) at net.openid.appauth.BrowserHandler.<init>(BrowserHandler.java:61) at net.openid.appauth.AuthorizationService.<init>(AuthorizationService.java:101)