I am using mendix 8.18.1 version. trying to complete the rapid crash course in mendix academy learning path. In which i have created one new entity button and another for planning that entity where I have created a microflow to plan that entity, which is similar as shown in the learning path. also not having any compilation errors. but while running project on local server it throws some runtime error.
I see that you have opend multiple instances of the app in different tabs.
When changing the model and re-running the app, data in other tabs might cause conflict, since these were created using the old page.
Close all tabs
stop the app (not re-run)
Start the app again
If you still have an error; your microflow has a bug.