Question: I have a problem with my code, even though it hasn't been modified in any way. It just suddenly threw this message. As you can see on the left, that they are all in the correct package, and have correct names.  

What can I do to fix this problem?

[![enter image description here](https://i.stack.imgur.com/ySp3u.png)](https://i.stack.imgur.com/ySp3u.png)

Answer: 
[Clear](https://stackoverflow.com/questions/8689780/how-to-clear-the-cache-in-netbeans/10722287#10722287) the cache to fix it. In Windows, cache is located at:

```
C:\Users\username\AppData\Local\NetBeans\...

```

On Linux, cache is at:

```
/home/username/.cache/netbeans/...

```

After clearing the cache restart netbeans.
I ran into this problem after we moved our NFS mount point containing my root project directory.

It seems there were some references to the old mount point in the `.nb-gradle` directory.

I closed all the projects in Netbeans and terminated Netbeans. I moved `.nb-gradle`to `hidden.nb-gradle` (*and .nb-gradle-properties to hidden.nb-gradle-properties for good measure*). I restarted NetBeans and reopened the root project (*which auto-opened the subprojects*). 

The `does not exist` message and all cascaded errors went away. A new `.nb-gradle` directory was created in the root project directory. The `.nb-gradle-properties` file was not re-created.