The forbiddenPatterns task failed - Plugin

error to run
./gradlew clean build

and the lines are blank, there is no code. Then why the error?

The :forbiddenPatterns task failed.View task in console log

Found invalid patterns: - tab on line 39 of src/test/java/org/devmaster/elasticsearch/plugin/RecurringSearchScriptTests.java - tab on line 40 of src/test/java/org/devmaster/elasticsearch/plugin/RecurringSearchScriptTests.java - tab on line 41 of src/test/java/org/devmaster/elasticsearch/plugin/RecurringSearchScriptTests.java

This sounds as if the lines are not fully emtpy. Can you check if they maybe only contain a tab but nothing else (this way they would look empty, but are not).

You can enable/disable the forbidden patterns task in your gradle build, if you need to as well (even though I'd recommend to keep it enabled).