Message type: E = Error
Message class:  RMSL - Labeling Application Messages 
Message number: 057
Message text: Invalid activity type
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 RMSL057 "Invalid activity type" typically occurs in the context of SAP's Resource Management System (RMS) or related modules where activity types are defined and utilized. This error indicates that the system has encountered an activity type that is not recognized or is not valid for the operation being performed.
Cause: Incorrect Activity Type: The activity type specified in the transaction or configuration does not exist in the system.
Configuration Issues: The activity type may not be properly configured or activated in the system. Data Entry Errors: There may be a typographical error in the activity type entered by the user. Authorization Issues: The user may not have the necessary authorizations to access the specified activity type. Missing Master Data: The required master data for the activity type may not be set up in the system.
Solution: Verify Activity Type: Check the activity type entered in the transaction. Ensure that it is spelled correctly and
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
RMSL056 Label set is being edited by user &1
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
RMSL055 Ingredient cannot be deleted
What causes this issue?  The item for deletion is an ingredient that cannot be deleted.System Response  The system issues an error message and will no...
RMSL058 No change authorization for label sets
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
RMSL059 You do not have authorization to display label sets
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.