Remote debugging: No connection to Wildfly 14 on OpenJDK 11 at port 8787

The cause lies in the default behaviour that changed with Java 9 according to this answer: Beginning with Java 9, the JVM only accepts local connections unless otherwise specified.

Therefore the solution is fairly easy:

While with Java 8 it is sufficient to start Wildfly with --debug, with Java 9 I needed to change this to --debug *:8787.

In my case, I was using Java 8 in my machine, but the remote Wildfly instance was running on Java 11.

When I changed my Java version to 11, it worked.

For jdk 11,you should use

-agentlib:jdwp=transport=dt_socket,address=*:8787,server=y,suspend=n

instead.