Message type: E = Error
Message class:  WRF_PRC_OTB - Purchasing, Open-To-Buy, Seasonal Procurement Messages 
Message number: 206
Message text: No entry in EKKO
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.
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.
The SAP error message WRF_PRC_OTB206 indicates that there is "No entry in EKKO," which typically means that the system is unable to find a corresponding entry in the EKKO table (the purchasing document header table) for the operation you are trying to perform. This error often occurs in the context of procurement processes, such as when trying to create or process purchase orders or related documents. Causes: Missing Purchase Order: The most common cause is that the purchase order you are trying to reference does not exist in the EKKO table. Incorrect Document Type: The document type you are using may not be valid or may not correspond to an existing entry in EKKO. Data Entry Errors: There may be typographical errors in the purchase order number or other related fields. Document Deletion: The purchase order may have been deleted or archived, making it unavailable for the current operation. Authorization Issues: The user may not have
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
WRF_PRC_OTB205 Purchasing document &1 has more than one budget number
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
WRF_PRC_OTB204 All items subject to OTB restriction
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
WRF_PRC_OTB207 No entry in EKPO
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
WRF_PRC_OTB208 No suitable entry in EKET
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
Click on this link to search all SAP messages.