I always get the exception like below(Still work ,but what's the problem?):

Directory Tooltips4Vaadin
1

I always get the exception like below(Still work ,but what’s the problem?):

Exception in thread "dev.mett.vaadin.tooltip.TooltipsCleaner" java.lang.NullPointerException
	at java.util.LinkedList$ListItr.next(LinkedList.java:893)
	at dev.mett.vaadin.tooltip.TooltipsCleaner.cleanup(TooltipsCleaner.java:49)
	at dev.mett.vaadin.tooltip.TooltipsCleaner.lambda$new$0(TooltipsCleaner.java:30)
	at java.lang.Thread.run(Thread.java:745)
2

Thank you for posting this stacktrace.
I added an issue in the repo: https://gitlab.com/gsedlacz/tooltips4vaadin/issues/16

It looks like a trivial issue. Ill most likely fix it on the weekend.

Best Regards
Gerrit Sedlaczek

3

Thank you.