[이클립스] call Hierarchy 안될때

1. Exit Eclipse  이클립스를 나간다. 
2. Go into Workspace Directory/.metadata/.plugins/org.eclipse.jdt.core "    워크스페이스/.metadata/.plugins/org.eclipse.jdt.core" 이동
3. Delete savedIndexNames.txt " savedIndexNames.txt " 삭제 
4. Delete all *.index " *.index "삭제
5. Start Eclipse 이클립스 재시작

해결됨. 

출처 : 

https://stackoverflow.com/questions/43489171/open-call-hierarchy-in-eclipse-not-working