Not sure what triggered it but got about 10 of these in my error log:

The error message is empty in the error log view; only the stack trace reveals details.

org.eclipse.jface.text.BadLocationException
at org.eclipse.jface.text.ListLineTracker.getLineNumberOfOffset(ListLineTracker.java:140)
at org.eclipse.jface.text.AbstractLineTracker.getLineNumberOfOffset(AbstractLineTracker.java:161)
at org.eclipse.jface.text.AbstractDocument.getLineOfOffset(AbstractDocument.java:915)
at org.eclipse.core.internal.filebuffers.SynchronizableDocument.getLineOfOffset(SynchronizableDocument.java:398)
at org.jboss.tools.jst.web.kb.internal.validation.ValidationErrorManager.addError(ValidationErrorManager.java:223)
at org.jboss.tools.jst.web.kb.internal.validation.ValidationErrorManager.addError(ValidationErrorManager.java:259)
at org.jboss.tools.jst.web.kb.internal.validation.ValidationErrorManager.addError(ValidationErrorManager.java:175)
at org.jboss.tools.jst.web.kb.internal.validation.ValidationErrorManager.addError(ValidationErrorManager.java:126)
at org.jboss.tools.jst.web.kb.internal.validation.ValidationErrorManager.addError(ValidationErrorManager.java:140)
at org.jboss.tools.cdi.internal.core.validation.CDICoreValidator.validateInjectionPoint(CDICoreValidator.java:1213)
at org.jboss.tools.cdi.internal.core.validation.CDICoreValidator.validateBean(CDICoreValidator.java:440)
at org.jboss.tools.cdi.internal.core.validation.CDICoreValidator.validateAll(CDICoreValidator.java:268)
at org.jboss.tools.jst.web.kb.internal.validation.ValidatorManager.validateAll(ValidatorManager.java:116)
at org.jboss.tools.jst.web.kb.internal.validation.ValidatorManager.validateInJob(ValidatorManager.java:81)
at org.eclipse.wst.validation.internal.operations.ValidatorJob.run(ValidatorJob.java:78)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)