IntelliJ IDEA can't setup JDK

Question

I'm trying to setup JDK in IntelliJ IDEA and whatever I do, or whatever JDK version I select, nothing happens. The following situation remains:

So I told IDEA what JDK it should use, but it still asks me to setup a JDK. Is this a bug or am I missing something? Can I apply any workaround to make everything work as usual?

ADDITION

The steps which I go through setting up the JDK: situation before setting up:

the first step:

the second step:

the third step:

the situation after setting up JDK:

SDKs:

module settings:

Answer 1

File | Invalidate Caches is the first thing you should try in case of such issues.

Answer 2

I followed below steps

1. Press F4
2. Select Modules in Project Settings
3. Set up Module SDK from the drop down or add the new one.
4. Apply & OK

Answer 3

In my case just File | Invalidate Caches and Restart did not work. Upon Right clicking the project and going to Module Settings , I had no SDK selected under Project Settings->Project.

Answer 4

I was seeing this exception in the console:

NoClassDefFoundError: com/intellij/remote/RemoteSdkConnectionAcceptor

which was caused by the python community edition plugin on Intellij IDEA 2016.2.5.

After updateing/disableing the plugin, I was able to setup the SDK again.

Answer 5

Select your modul in the "Project View" and press F4 in the "Project Setting"select "Module". In the "Module Settings" overview you can add/remove the Modul SDK.

Answer 6

Following this worked for me :

Select your module in Project View

Press F4

Go to SDK

Select you SDK

Make sure you have various jars in there. Else, select proper directory.

In my case, even though correct directory was selected classpath,sourcepath etc were empty.

So I had to select jdk installation directory one more time, which loaded all the jars and solved the problem.