How to fix error: "symbol lookup error: /usr/local/lib/libQt5DBus.so.5: undefined symbol"?

I was using GNS3 network simulator fine for a while & then after few days When I start GNS3 Network Simulator, it is giving out following error, not sure what caused this. **$ sudo gns3** GNS3 GUI version 1.5.2 Copyright (c) 2007-2016 GNS3 Technologies Inc. your locale en_IN.ISO8859-1 encoding is not UTF-8, switching to the UTF-8 version... 2016-12-23 22:57:53 INFO logger.py:107 Log level: INFO /usr/share/gns3/gns3-gui/bin/python: symbol lookup error: /usr/local/lib/libQt5DBus.so.5: undefined symbol: _Z28qEnvironmentVariableIntValuePKcPb I tried reinstalling gns3 but the error persisted. While Un-installing, I got the following warnings: dpkg: warning: while removing gns3-gui, directory '/usr/share/gns3/gns3-gui/lib/python3.4/__pycache__' not empty so not removed dpkg: warning: while removing gns3-gui, directory '/usr/share/gns3/gns3-gui/bin' not empty so not removed Removing gns3-server (1.5.2~trusty1) ... dpkg: warning: while removing gns3-server, directory '/usr/share/gns3/gns3-server/lib/python3.4/__pycache__' not empty so not removed dpkg: warning: while removing gns3-server, directory '/usr/share/gns3/gns3-server/bin' not empty so not removed So I removed /usr/share/gns3* and then tried installing GNS3 no luck. Tried the following suggestions made in this answer Commented the line "/usr/local/lib" in the file /etc/ld.so.conf.d/libc.conf but no use. Also when I tried installing GNS3 through Ubuntu Software Center