How To Fix SY491 - Internal tables and strings do not have instances

SY491 - Overview

• Message type: E = Error

• Message class: SY - ABAP/4 system messages

• Message number: 491

• Message text: Internal tables and strings do not have instances

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?

First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).

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 SY491 - Internal tables and strings do not have instances ?

  The SAP error message SY491 ("Internal tables and strings do not have instances") typically occurs in ABAP programming when there is an attempt to access an internal table or a string that has not been properly instantiated or initialized. This error can arise in various scenarios, such as when trying to read from an internal table that has not been filled with data or when trying to manipulate a string that has not been defined.
  Causes:
  
  Uninitialized Internal Table: The internal table has been declared but not filled with any data before it is accessed.
  Uninitialized String: A string variable is declared but not assigned any value before it is used.
  Incorrect Logic: The logic in the program may lead to a situation where the internal table or string is expected to have data, but it does not.
  Scope Issues: The internal table or string may be declared in a different scope and is not