I had Splunk V6.3.1 with DB Connect 2 V2.0.6 working fine.
Because of the incorrect date reporting I upgraded DB Connect 2 to V2.1.2, which fixed the issue.
Then I decided to upgrade Splunk to V6.3.2 which broke DB Connect. In the Explorer window Connections were not loading but everything worked fine.
In the splunkd.log the following error are getting logged everytime Connections page is accessed.
"02-11-2016 14:45:27.549 -0600 ERROR AdminManagerExternal - Stack trace from python handler:\nTraceback (most recent call last):\n File "/dev/splunk-test/splunk/lib/python2.7/site-packages/splunk/admin.py", line 70, in init\n hand.execute(info)\n File "/dev/splunk-test/splunk/lib/python2.7/site-packages/splunk/admin.py", line 529, in execute\n if self.requestedAction == ACTION_LIST: self.handleList(confInfo)\n File "/dev/splunk-test/splunk/etc/apps/splunk_app_db_connect/bin/rh_connection_types.py", line 61, in handleList\n self.addDriverInfo(obj, info)\n File "/dev/splunk-test/splunk/etc/apps/splunk_app_db_connect/bin/rh_connection_types.py", line 32, in addDriverInfo\n driverClass = ent['jdbcDriverClass']\n File "/dev/splunk-test/splunk/lib/python2.7/site-packages/splunk/entity.py", line 535, in getitem\n return self.properties[key]\nKeyError: 'jdbcDriverClass'\n
02-11-2016 14:45:27.549 -0600 ERROR AdminManagerExternal - Unexpected error "" from python handler: "'jdbcDriverClass'". See splunkd.log for more details."
Then I upgraded Splunk to 6.3.3 to see if it resolves the issue but no go. I upgraded DB Connect 2 to V 2.1.3 still the same issue is getting reported in the logs and Connections page is not getting loaded.
Removed DB connect 2 app and reinstalled it, first 2.0.6, then 2.1.2 and and last 2.1.3. Also upgraded Splunk to V6.3.3. Everything seems to work now and it looked like some files might have got corrupt during the upgrades.