--- p7zip_15.14.1/CPP/7zip/Archive/7z/7zIn.cpp.1	2016-12-04 22:30:12.398535943 +0300
+++ p7zip_15.14.1/CPP/7zip/Archive/7z/7zIn.cpp	2016-12-04 22:33:25.534241347 +0300
@@ -1097,7 +1097,8 @@
       if (CrcCalc(data, unpackSize) != folders.FolderCRCs.Vals[i])
         ThrowIncorrect();
   }
-  HeadersSize += folders.PackPositions[folders.NumPackStreams];
+  if (folders.PackPositions) 
+    HeadersSize += folders.PackPositions[folders.NumPackStreams];
   return S_OK;
 }