Message type: E = Error
Message class:  FKKZWF - Doubtful Item Entry/Individual Value Adjustment 
Message number: 006
Message text: Company code & can be adjusted to valuation areas
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 FKKZWF006 indicates that there is a mismatch between the company code and the valuation areas in the context of Financial Accounting and Controlling (FI/CO) modules, particularly in the area of contract accounts receivable and payable (FI-CA). This error typically arises when there is an attempt to post or process transactions that involve different valuation areas that are not aligned with the specified company code.
Cause: Mismatch in Configuration: The company code is not properly configured to allow for the valuation areas that are being used in the transaction. Incorrect Master Data: The master data for the customer or vendor may not be set up correctly, leading to inconsistencies between the company code and valuation areas. Valuation Area Settings: The valuation area settings in the configuration may not be aligned with the company code settings.
Solution: Check Configuration: Go to the configuration settings in SAP (Transaction SPRO). Navigate to Financial Accounting (New) > Accounts Receivable
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
FKKZWF005 Company code & successfully adjusted to valuation areas
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
FKKZWF004 Company code &1 doubtful entry data transferable to new tables
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
FKKZWF007 Company code & already adjusted to valuation areas
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
FKKZWF008 Company code &1 doubtful entry data already transferred to new tables
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.