I am having the same issue as others on this thread. I ran the diagnostic test and this is what was found...
2017-06-10 10:22:37.581 SCTool[783:51960] Fail to invoke helper tool: No such file or directory (rc=-1)
Assertion failed: (false), function -[HelperTool executeWithArgs:withObject:], file HelperTool.mm, line 106.