Android Studio 3.0 - Unable to save settings: Failed to save settings. Please restart Android Studio

Finally, I resolved by creating new Android project and moved my all files into it. This issue got because of existing settings in the old project.

It may useful for someone.

Update:

Go to File--> Project Structure --> Check Use Embedded JDK (Recommended)

Ref:

@DSlomer64

I found an easier way.

Instead of 'creating new Android project and moved my all files into it' as Shylendra Madda did, I merely deleted the .idea folder.

1) Go to File--> Settings -->Plugins Disable any plugins not loaded (i.e. red in color)

2) Enable the one plugin, Android Support

3) Right-click on your 'app' directory (contains your module gradle.build file) in Android Studio and select 'Show in Explorer' --- this opens that directory.

4) Quit Android Studio. Get out of any and all instances of Android Studio to allow you to then delete the fold, .idea, in that directory.

5) Restart AS, you'll notice the project will not come up -- you'll have to pick in the dialog window that appears. That's ok. Pick it, and it will 'rebuild' the folder, .idea.

6) Go to File--> Settings -->Plugins Enable any and all plugins

7) You won't get the message ever again... ;)

Cheers.

I think this problem is because your project in a drive that you don't have sufficient permissions to access. I faced that problem so I recreate my project in home directory (Ubuntu) instead ntfs drive and the problem is gone.