Hi, Pradeep.
Is the “left out” variable the last on the list? For example, the first 19 are successful; the last 1 is not? Or, is the position of the 20th variable random?
Have you confirmed that $tid is present in the pipeline? You can try invoking pub.flow.savePipeline in your Flow and then check for variable existence using pub.flow.restorePipeline.
If you are unfamiliar with using these Built-in Services, read up on them in the Built-In Services guide in your Developer’s /doc folder.
#Flow-and-Java-services#Integration-Server-and-ESB#webMethods