Module function cannot be found for the fully qualified name

[SAGARSURI]

I am trying to run my first program.

fun main(args: Array<String>): Unit = io.ktor.server.netty.EngineMain.main(args)

@Suppress("unused") // Referenced in application.conf
@kotlin.jvm.JvmOverloads
fun Application.module(testing: Boolean = false) {
    routing {
        get("/"){
            call.respondText("Hello World")
        }
        get("/hello"){
            call.respondText("Hello Ktor")
        }
    }
}

But I get below error everytime:

Exception in thread "main" java.lang.ClassNotFoundException: Module function cannot be found for the fully qualified name 'com.sagar.ApplicationKt.module'
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.executeModuleFunction(ApplicationEngineEnvironmentReloading.kt:367)
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.access$executeModuleFunction(ApplicationEngineEnvironmentReloading.kt:33)
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading$instantiateAndConfigureApplication$1$$special$$inlined$forEach$lambda$1.invoke(ApplicationEngineEnvironmentReloading.kt:287)
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading$instantiateAndConfigureApplication$1$$special$$inlined$forEach$lambda$1.invoke(ApplicationEngineEnvironmentReloading.kt:33)
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.avoidingDoubleStartupFor(ApplicationEngineEnvironmentReloading.kt:320)
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.access$avoidingDoubleStartupFor(ApplicationEngineEnvironmentReloading.kt:33)
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading$instantiateAndConfigureApplication$1.invoke(ApplicationEngineEnvironmentReloading.kt:286)
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading$instantiateAndConfigureApplication$1.invoke(ApplicationEngineEnvironmentReloading.kt:33)
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.avoidingDoubleStartup(ApplicationEngineEnvironmentReloading.kt:302)
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.instantiateAndConfigureApplication(ApplicationEngineEnvironmentReloading.kt:284)
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.createApplication(ApplicationEngineEnvironmentReloading.kt:137)
	at io.ktor.server.engine.ApplicationEngineEnvironmentReloading.start(ApplicationEngineEnvironmentReloading.kt:257)
	at io.ktor.server.netty.NettyApplicationEngine.start(NettyApplicationEngine.kt:116)
	at io.ktor.server.netty.NettyApplicationEngine.start(NettyApplicationEngine.kt:22)
	at io.ktor.server.engine.ApplicationEngine$DefaultImpls.start$default(ApplicationEngine.kt:56)
	at io.ktor.server.netty.EngineMain.main(EngineMain.kt:21)
	at com.sagar.ApplicationKt.main(Application.kt:9)

kotlin-version: 1.3.31

[laxtiz]

i have same.
if build application with ktor 1.1.5, all ok.
but build with ktor 1.2.0 then run it, i got some error like your.
i don't know why.

[cy6erGn0m]

This is duplicate for #1132 and should be fixed in 1.2.1 that is already on the way.

[homailali]

For me it was occuring because the package name specified in the application.yaml (under resources folder) was not the same as where my Application file was residing so check whether in your case it is correct or not

src/
└── main/
----└── kotlin/
-------└── example/
------------└── com/
---------------└── application
-------------------└── Application.kt
---------------└── plugins/
-------------------└── Routing.kt

for this folder structure the application.yaml would be

ktor:
application:
modules:
- example.com.application.ApplicationKt.module // this is what you need to check
deployment:
port: 8080