Message type: E = Error
Message class:  APPL_MM_PUR_SOS - Messages for Source of Supply 
Message number: 015
Message text: You are not authorized to use condition type &1
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 APPL_MM_PUR_SOS015 indicates that a user is not authorized to use a specific condition type in the context of purchasing or materials management. This error typically arises when a user attempts to create or modify a purchasing document (like a purchase order or contract) that involves a condition type for which they do not have the necessary authorizations.
Cause: Authorization Issues: The user does not have the required authorization to use the specified condition type. This could be due to missing roles or authorizations in their user profile. Configuration Settings: The condition type may be restricted in the system configuration, limiting its use to certain user roles or groups. User Role Changes: If a user's role has been changed or if they have been assigned a new role that does not include the necessary authorizations, this error may occur.
Solution: Check User Authorizations: Use transaction code SU53 immediately after encountering the error to see
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
APPL_MM_PUR_SOS014 You are not authorized to maintain pricing conditions
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
APPL_MM_PUR_SOS013 Valid To date is before the "Valid From" date of period from &1 to &2
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
APPL_MM_PUR_SOS_SL000 User &1 has a Draft for the Material :&2 Plant:&3 Combination
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
APPL_MM_PUR_SOS_SL001 Active Source List exists for Material :&1 Plant:&2 Combination
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.