How To Fix FRE644 - RFC undefined Error

FRE644 - Overview

• Message type: E = Error

• Message class: FRE - F&R CON R/3 - Messages

• Message number: 644

• Message text: RFC undefined Error

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

Unfortunately, there isn't any extra information in this error notice.

What else can you do?

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Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.

You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.

Smart SAP Assistant

• What is the cause and solution for SAP error message FRE644 - RFC undefined Error ?

  The SAP error message FRE644, which indicates "RFC undefined error," typically arises in the context of Remote Function Call (RFC) communications between SAP systems or between an SAP system and an external system. This error can occur due to various reasons, and understanding the cause is essential for troubleshooting and resolving the issue.
  Causes of FRE644 RFC Undefined Error
  
  
  Network Issues: Problems with the network connection between the SAP systems can lead to RFC errors. This includes issues like firewalls blocking the connection, network outages, or misconfigured network settings.
  
  
  RFC Destination Configuration: The RFC destination may not be correctly configured in the SAP system. This includes incorrect parameters such as the target system's IP address, system number, or client.
  
  
  Authorization Issues: The user credentials used for the RFC call may not have the necessary authorizations to execute the requested function module.
  
  
  Function Module Not Found: The function module being called may not exist in the