Message type: E = Error
Message class:  /SAPDMC/LSMW_AUX_010 -  
Message number: 018
Message text: Assign files first.
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 /SAPDMC/LSMW_AUX_010018 Assign files first typically occurs in the context of using the Legacy System Migration Workbench (LSMW) in SAP. This error indicates that the system expects you to assign files to the LSMW project before proceeding with the data migration process.
Cause: The error is triggered when you attempt to execute a step in the LSMW process without having first assigned the necessary files that contain the data to be migrated. This is a common oversight, especially if you are new to using LSMW or if you are working with a complex migration project.
Solution: To resolve this error, follow these steps: Open LSMW: Go to the LSMW transaction in your SAP system. Select Your Project: Choose the appropriate project, subproject, and object that you are working on. Navigate to the File Assignment Step: Go to the "Maintain Files" step in the LSMW menu. Here, you will need to assign the files that contain the
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
/SAPDMC/LSMW_AUX_010017 Specify files first.
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SAPDMC/LSMW_AUX_010016 Define field mapping and rule first.
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SAPDMC/LSMW_AUX_010019 You only have authorization '&2' and not '&1'.
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SAPDMC/LSMW_AUX_010020 You do not have the authorization for project &.
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.