When a +-prefixed number called you and you try to call it back using the button in the indicator, it fails with the attached .crash file, url-dispatcher tool reports:
** (process:26240): WARNING **: Unable to dispatch url 'tel:///%2B48508xxxxxx':GDBus.Error:com.canonical.URLDispatcher.BadURL: URL 'tel:///%2B48508xxxxxx' is not handleable by the URL Dispatcher
ProblemType: RecoverableProblem
DistroRelease: Ubuntu 14.04
Package: telephony-service 0.1+14.04.20140306-0ubuntu1
Uname: Linux 3.4.0-5-mako armv7l
ApportVersion: 2.13.3-0ubuntu1
Architecture: armhf
BadURL: tel:///%2B48508xxxxxx
CurrentDesktop: Unity
Date: Fri Mar 14 19:06:51 2014
DuplicateSignature: url-dispatcher;bad-url;tel:///%2B48508xxxxxx
ExecutablePath: /usr/bin/telephony-service-indicator
ExecutableTimestamp: 1394099254
InstallationDate: Installed on 2014-03-14 (0 days ago)
InstallationMedia: Ubuntu Trusty Tahr (development branch) - armhf (20140314)
LocalLibraries: /android/system/lib/libGLES_trace.so /android/system/lib/libcorkscrew.so /android/system/lib/libcutils.so /android/system/lib/libgccdemangle.so /android/system/lib/libc.so /android/system/lib/libdsyscalls.so /android/system/lib/libstlport.so /android/system/lib/libEGL.so /android/system/lib/libGLESv2.so /android/system/lib/libstdc++.so /android/system/lib/libutils.so /android/system/lib/liblog.so /android/system/lib/libm.so
ProcCmdline: /usr/bin/telephony-service-indicator
ProcCwd: /
SourcePackage: telephony-service
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm autopilot cdrom dialout dip nopasswdlogin plugdev sudo tty video
please test to see if still valid