Symbol error? What does this mean?

Here's the error code...     warning: [options] bootstrap class path not set in conjunction with -source 1.6
C:\Pylo\MCreator175\forge\build\sources\main\java\mod\mcreator\modname.java:40: error: cannot find symbol
 mcreator_ultimatiumore mcreator_1 = new mcreator_ultimatiumore();
 ^
  symbol:   class mcreator_ultimatiumore
  location: class modname
C:\Pylo\MCreator175\forge\build\sources\main\java\mod\mcreator\modname.java:41: error: cannot find symbol
 mcreator_ultimatiumIngot mcreator_2 = new mcreator_ultimatiumIngot();
 ^
  symbol:   class mcreator_ultimatiumIngot
  location: class modname
C:\Pylo\MCreator175\forge\build\sources\main\java\mod\mcreator\modname.java:42: error: cannot find symbol
 mcreator_woodmultitool mcreator_3 = new mcreator_woodmultitool();
 ^
  symbol:   class mcreator_woodmultitool
  location: class modname
C:\Pylo\MCreator175\forge\build\sources\main\java\mod\mcreator\modname.java:43: error: cannot find symbol
 mcreator_stonemultitool mcreator_4 = new mcreator_stonemultitool();
 ^
  symbol:   class mcreator_stonemultitool
  location: class modname
C:\Pylo\MCreator175\forge\build\sources\main\java\mod\mcreator\modname.java:44: error: cannot find symbol
 mcreator_ironmultitool mcreator_5 = new mcreator_ironmultitool();
 ^
  symbol:   class mcreator_ironmultitool
  location: class modname
C:\Pylo\MCreator175\forge\build\sources\main\java\mod\mcreator\modname.java:40: error: cannot find symbol
 mcreator_ultimatiumore mcreator_1 = new mcreator_ultimatiumore();
                                         ^
  symbol:   class mcreator_ultimatiumore
  location: class modname
C:\Pylo\MCreator175\forge\build\sources\main\java\mod\mcreator\modname.java:41: error: cannot find symbol
 mcreator_ultimatiumIngot mcreator_2 = new mcreator_ultimatiumIngot();
                                           ^
  symbol:   class mcreator_ultimatiumIngot
  location: class modname
C:\Pylo\MCreator175\forge\build\sources\main\java\mod\mcreator\modname.java:42: error: cannot find symbol
 mcreator_woodmultitool mcreator_3 = new mcreator_woodmultitool();
                                         ^
  symbol:   class mcreator_woodmultitool
  location: class modname
C:\Pylo\MCreator175\forge\build\sources\main\java\mod\mcreator\modname.java:43: error: cannot find symbol
 mcreator_stonemultitool mcreator_4 = new mcreator_stonemultitool();
                                          ^
  symbol:   class mcreator_stonemultitool
  location: class modname
C:\Pylo\MCreator175\forge\build\sources\main\java\mod\mcreator\modname.java:44: error: cannot find symbol
 mcreator_ironmultitool mcreator_5 = new mcreator_ironmultitool();
                                         ^
  symbol:   class mcreator_ironmultitool
  location: class modname
Note: C:\Pylo\MCreator175\forge\build\sources\main\java\mod\mcreator\mcreator_omniTool.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
10 errors
1 warning FAILURE: Build failed with an exception. * What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details. * Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.