Trying to compile but get JAVA compilation errors because of "_"

compile:
    [javac] Compiling 139 source files to C:\....main\deployment\run\bin
    [javac] C:\....main\javasource\restservices\publish\RestServiceHandler.java:250: warning: '_' used as an identifier
    [javac]             String _) {
    [javac]                    ^
    [javac]   (use of '_' as an identifier might not be supported in releases after Java SE 8)
    [javac] C:\....main\javasource\mxmodelreflection\actions\ValidateTokensInMessage.java:43: error: cannot find symbol
    [javac]         return TokenReplacer.validateTokens(this.getContext(), this.Text, __TokenList);
    [javac]                                                                    ^
    [javac]   symbol: variable Text
    [javac] Note: C:\....main\javasource\restservices\util\JCIFS_NTLMScheme.java uses or overrides a deprecated API.
    [javac] Note: Recompile with -Xlint:deprecation for details.
    [javac] Note: C:\....main\javasource\com\mendix\core\Core.java uses unchecked or unsafe operations.
    [javac] Note: Recompile with -Xlint:unchecked for details.
    [javac] 1 error
    [javac] 1 warning

Anyone have an idea how to fix this??