Mule 4 - flows suddently stopped initializing, warning about some mysterious yml file occurs, MUnit test started throwing unexpected errors - mule

Question

I was working on my Mule 4 application today, and suddenly my Anypoint Studio went crazy. When I was trying to run my application, i recieved an error that a port used by the application is already in use. Nothing unusual, but when I have restarted my PC and wanted to run the app again, suspicious information showed up in the console:
INFO 2021-05-25 12:40:21,056 [WrapperListener_start_runner] [processor: ; event: ] org.mule.runtime.core.internal.construct.AbstractFlowConstruct: Flow ImportPendingCorrectionsFlow has not been started
INFO 2021-05-25 12:40:21,056 [WrapperListener_start_runner] [processor: ; event: ] org.mule.runtime.core.internal.construct.FlowConstructLifecycleManager: Starting flow: ImportInvoicesFlow
INFO 2021-05-25 12:40:21,056 [WrapperListener_start_runner] [processor: ; event: ] org.mule.runtime.core.internal.construct.FlowConstructLifecycleManager: Stopping flow: ImportInvoicesFlow
and the same message for all flows in my application.
Then I tried to run an existing MUnit test, which was running correctly since a month or more, and I recieved this error:
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Running test: ImportInvoicesFlowTestWithIncorrectVehicleCount - Test +
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java.lang.AssertionError: The error ID thrown does not match the expected one. expected:<[APP:VALIDATION]> but was:<[HTTP:CONNECTIVITY]>
at org.mule.munit.runner.flow.TestFlow.run(TestFlow.java:313)
Caused by: java.io.IOException: Remotely closed
Caused by: java.io.IOException: Remotely closed
This is indeed very strange - as this flow has nothing to do with HTTP at all.
Finally, I have discovered a very strange WARN in the console:
WARN 2021-05-25 13:04:35,613 [Mule.app.deployer.monitor.1.thread.1] [processor: ; event: ] com.mulesoft.agent.configuration.descriptor.YamlMuleAgentDescriptor: Descriptor file /home/xxxxxxx/apps/AnypointStudio-7.7.0-linux64/AnypointStudio/plugins/org.mule.tooling.server.4.3.0.ee_7.3.5.202105101830/mule/conf/invoices-esb-mule4-app.yml not found.
I don't know what's happening here, i have never ever created such a file as invoices-esb-mule4-app.yml. I assume that this is some kind of a configuration file created by Mule itself basing on the application name. The path is strange here, as the workspace I'm working on is in /home/xxxxxxx/AnypointStudio7/workspace-2/
Other information that can be helpful (or not)
I was working on an ApiKit SOAP service, but still, it worked fine.
At one moment, I have misclicked Mule Design perspective and clicked Api Desing perspective, which ended in an application crash, but it SEEMED to be working correctly after starting Anypoint Studio again.
Is anyone having an idea what could have happened to my Anypoint Studio or my application?

Answer 1

I encountered a similar problem in which the logs said FlowConstructLifecycleManager: Starting flow [flow name], then FlowConstructLifecycleManager: Stopping flow [flow name], then AbstractFlowConstruct: Flow [flow name] has not been started. Then repeat those three with the next flow.
After spending more than a day trying various solutions, my team tried going to Run, Run Configurations, select Mule Applications, select the Mule application, General tab, "Clear Application Data:" and changing it to "Always". It had been "Never". After making this change and running it again, it started working. Hope this helps you or someone else with a similar "Stopping flow" problem.

Answer 2

The YML could be a per application configuration file created by the Runtime Manager Agent. It is strange that it is create in an execution inside Studio though. Check if the /home/xxxxxxx/apps/AnypointStudio-7.7.0-linux64/AnypointStudio/plugins/org.mule.tooling.server.4.3.0.ee_7.3.5.202105101830/mule/conf/mule-agent.yml is referencing it.