Pipeline not starting

kindly help pipeline action failing
:exception=>#<NoMethodError: undefined method `toCharArray' for nil:NilClass>
Could not execute action: PipelineAction::Create

after add truststore

index => "Sample"
    user => "LogstashUser"
    password => "*****"
	ssl => true
	ssl_certificate_verification => true
	keystore => "/logstash-7.6.1/config/logstashca/sample.p12"
    truststore => "/logstash-7.6.1/config/logstashca/sample.p12"
	truststore_password => "*******"