Execute sql Oracle statement

At first i execute the same script it work well. Then after few times execute the same test case it return below error:

aused by: java.lang.Error: Unresolved compilation problem:

at com.amway.magic.SQLStatement.<init>(SQLStatement.groovy:1)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at java.lang.Class.newInstance(Class.java:442)
at com.kms.katalon.core.main.CustomKeywordDelegatingMetaClass.invokeStaticMethod(CustomKeywordDelegatingMetaClass.java:45)
... 33 more

2019-07-24 10:53:58.356 ERROR c.k.katalon.core.main.TestCaseExecutor - :x: Test Cases/V2_Volume_Cases/V2_Volume_TC01_getBonusSchedules FAILED.
Reason:
java.lang.Error: Unresolved compilation problem:

at com.amway.magic.SQLStatement.<init>(SQLStatement.groovy:1)

please post the full console error
it seems like you are using a custom keyword the code would be helpful too

you need a destructor in the keyword to kill the connection object no matter connection was succsesfull or not. or a better constructor