[android][error]project refresh failed - cache.properties.lock

[message]

Gradle 'Project Name' project refresh failed

Error:Timeout waiting to lock buildscript class cache for build file 

...

It is currently in use by another Gradle instance.

Owner PID: *

Our PID: *

Owner Operation: *

Our operation: Initialize cache

Lock file: 

C:\ ... \.gradle\caches\ ... \ProjectScript\buildscript\cache.properties.lock

[environment]

android studio

[solution]

1. go to the folder & delete file - cache.properties.lock

if you can't delete for java then 

2. close android studio

3. retry 1.