SpringBoot java.lang.NoSuchMethodError: 'void org.springframework.util.Assert.isTrue(boolean, java.util.function.Supplier)'

Bug report: I am using the FileSystemWatcher, and when I call the addSourceDirectory function, I get the following error message:

java.lang.NoSuchMethodError: 'void org.springframework.util.Assert.isTrue(boolean, java.util.function.Supplier)'

It seems because 1 of the assertions is using a lambda function for the message, instead of String.

Comment From: wilkinsona

You are using an incompatible version of Spring Framework. org.springframework.util.Assert.isTrue(boolean, Supplier<String>) was added in Spring Framework 5.0.