I have the same problem as this post (In Corda, `No installed custom CorDapps.` on node's built-in webserver).
Here's what I did:
1. I'm using the Java version of Tokens-SDK, it has a different folder structure from the examples mentioned in the solution of that post (i.e. clients, contracts, and workflows are 3 separate modules rather than one module).
2. Here's my latest commit with the below mentioned changes:
https://github.com/adelRestom/corda-tokens-api/commit/4fc730b352a184c3848ef2455e0fbb9e712a4e2b
4. I created the class ExamplePlugin
inside clients
module
5. I created the file net.corda.webserver.services.WebServerPluginRegistry
inside clients
module
6. I updated build.gradle
under the root folder of the project and added cordapp project(":clients")
as a dependency (I'm not a gradle expert, but I assume that this should add this module to the jar file of the cordapp)
7. I ran ./gradlew jar
8. I uploaded the jar file to /opt/corda/cordapps
inside my google cloud VM
9. I started the node using run-corda.sh
10. I went to my browser and used the external IP address of my node with port 8080
11. I get No installed custom CordApps
Can you please have a look at my repository and see what am I missing?