Null ptr exception in SqlBase.g4

[parrt]

SqlBase.g4 gives

$ a4.7 SqlBase.g4 
warning(156): SqlBase.g4:951:7: invalid escape sequence
warning(156): SqlBase.g4:951:16: invalid escape sequence
warning(156): SqlBase.g4:951:41: invalid escape sequence
error(144): SqlBase.g4:951:15: multi-character literals are not allowed in lexer sets: '
Exception in thread "main" java.lang.NullPointerException
	at org.antlr.v4.automata.ParserATNFactory.elemList(ParserATNFactory.java:469)
	at org.antlr.v4.automata.ParserATNFactory.alt(ParserATNFactory.java:455)
	at org.antlr.v4.parse.ATNBuilder.alternative(ATNBuilder.java:559)
	at org.antlr.v4.parse.ATNBuilder.ruleBlock(ATNBuilder.java:293)
	at org.antlr.v4.automata.ParserATNFactory._createATN(ParserATNFactory.java:161)
	at org.antlr.v4.automata.LexerATNFactory.createATN(LexerATNFactory.java:120)
	at org.antlr.v4.Tool.processNonCombinedGrammar(Tool.java:389)
	at org.antlr.v4.Tool.process(Tool.java:354)
	at org.antlr.v4.Tool.processGrammarsOnCommandLine(Tool.java:321)
	at org.antlr.v4.Tool.main(Tool.java:168)

The '\" give that "multi-character literals are not ..." error. Should be better as that will be common.

[parrt]

Crap. Got too focused on error messages and antlr tests. forgot to test on SqlBase.g4! Now I get:

warning(156): SqlBase.g4:951:7: invalid escape sequence \"
warning(156): SqlBase.g4:951:16: invalid escape sequence \"
warning(156): SqlBase.g4:951:41: invalid escape sequence \"
error(144): SqlBase.g4:951:15: multi-character literals are not allowed in lexer sets: '\
Exception in thread "main" java.lang.NullPointerException
	at org.antlr.v4.automata.ParserATNFactory.elemList(ParserATNFactory.java:469)
...