Message type: E = Error
Message class:  CNVMBTRFC - Messages used in RFC Management and its objects 
Message number: 127
Message text: Destination &1 with version &2 with different clients (&3 <> &4)
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 CNVMBTRFC127 typically occurs in the context of a system conversion or migration process, particularly when using the SAP S/4HANA Migration Cockpit or similar tools. This error indicates that there is a mismatch in the client settings between the source and target systems during a remote function call (RFC).
Cause: The error message CNVMBTRFC127 is triggered when: The destination system (indicated by &1) has a different client version (&3) than the source system (&4). This can happen if the systems are not properly aligned in terms of client configuration, or if there are inconsistencies in the client settings between the source and target systems.
Solution: To resolve this error, you can take the following steps: Check Client Configuration: Verify that the client settings in both the source and target systems are correctly configured. Ensure that the clients are compatible and that the necessary configurations are in place. Review RFC Destination: Go to transaction SM59 in the SAP
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
CNVMBTRFC126 Destination &1 with version &2 with different system_id (&3 <> &4)
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNVMBTRFC125 No destination where to reenter the password
What causes this issue?  In the overview for reentering the passwords we have to enter the passwords for the destinations in the remote system. We hav...
CNVMBTRFC128 Modify destination failed (see table cnvmbtdest)
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNVMBTRFC129 Modify RFC versions failed (see table cnvmbtdestvers)
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.