I was working regularly in Arduino IDE 1.6.5 when suddenly it refused to launch. The splash screen hangs on "Starting..." and I need to force kill it (however, it does not show up as an app that has stopped responding). I downloaded and tried 1.6.10 to the same effect. I then went back to some older versions including 1.0.6 and none of them would launch.
I'm on OSX 10.10.5 and this machine has had a relatively static operating environment. I haven't updated anything that I know of, including Java, but the OS could have done something under the hood I'm not aware of.
When I try to launch, this is what comes up in the console (most of it is Greek to me):
8/7/16 8:52:07.819 AM locationd[98]: Location icon should now be in state 'Active'
8/7/16 8:52:08.327 AM com.apple.xpc.launchd[1]: (com.apple.quicklook[11940]) Endpoint has been activated through legacy launch(3) APIs. Please switch to XPC or bootstrap_check_in(): com.apple.quicklook
8/7/16 8:52:08.858 AM amfid[137]: /Applications/Arduino.app/Contents/MacOS/Arduino signature not valid: 0xfffefa2a
8/7/16 8:52:08.000 AM kernel[0]: proc 11947: load code signature error 4 for file "Arduino"
8/7/16 8:52:09.140 AM locationd[98]: NETWORK: requery, 0, 0, 0, 0, 9, items, fQueryRetries, 0, fLastRetryTimestamp, 492269502.1
8/7/16 8:52:09.912 AM locationd[98]: Location icon should now be in state 'Inactive'
8/7/16 8:52:10.116 AM WindowServer[197]: Received display connect changed for display 0x42803c2
8/7/16 8:52:10.135 AM WindowServer[197]: Found 27 modes for display 0x042803c2 [27, 0]
8/7/16 8:52:10.161 AM WindowServer[197]: Received display connect changed for display 0x3f003f
8/7/16 8:52:10.162 AM WindowServer[197]: Found 1 modes for display 0x003f003f [1, 0]
8/7/16 8:52:10.162 AM WindowServer[197]: Received display connect changed for display 0x3f0040
8/7/16 8:52:10.162 AM WindowServer[197]: Found 1 modes for display 0x003f0040 [1, 0]
8/7/16 8:52:10.162 AM WindowServer[197]: Received display connect changed for display 0x3f0041
8/7/16 8:52:10.162 AM WindowServer[197]: Found 1 modes for display 0x003f0041 [1, 0]
8/7/16 8:52:10.164 AM WindowServer[197]: CGXMuxAcknowledge: Posting glitchless acknowledge
8/7/16 8:52:10.195 AM WindowServer[197]: MPAccessSurfaceForDisplayDevice: Set up page flip mode on display 0x042803c2 device: 0x7f98d25057e0 isBackBuffered: 1 numComp: 3 numDisp: 3
8/7/16 8:52:10.337 AM WindowServer[197]: Received display connect changed for display 0x42803c2
8/7/16 8:52:10.338 AM WindowServer[197]: Found 1 modes for display 0x042803c2 [1, 0]
8/7/16 8:52:15.413 AM Spotlight[421]: CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 3. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
8/7/16 8:52:15.413 AM Spotlight[421]: CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 3. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
8/7/16 8:52:15.414 AM Spotlight[421]: CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 3. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
8/7/16 8:52:15.414 AM Spotlight[421]: CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 3. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
8/7/16 8:52:15.414 AM Spotlight[421]: CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 3. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
8/7/16 8:52:40.699 AM mdworker[11990]: code validation failed in the process of getting signing information: Error Domain=NSOSStatusErrorDomain Code=-67062 "The operation couldn’t be completed. (OSStatus error -67062.)" UserInfo=0x7fbd6ca11140 {SecCSArchitecture=i386}
8/7/16 8:52:41.387 AM mdworker[11989]: CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 8. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
8/7/16 8:52:41.503 AM mdworker[11989]: CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 8. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
8/7/16 8:52:41.528 AM mdworker[11989]: code validation failed in the process of getting signing information: Error Domain=NSOSStatusErrorDomain Code=-67062 "The operation couldn’t be completed. (OSStatus error -67062.)" UserInfo=0x7f91e375abc0 {SecCSArchitecture=i386}