Message type: E = Error
Message class:  FI - TR-FM Funds Management 
Message number: 195
Message text: System error: No document header exists (&1) &2 &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 FI195 ("System error: No document header exists") typically occurs in the Financial Accounting (FI) module when the system is unable to find a document header for a specified document number. This can happen for various reasons, and understanding the cause is crucial for resolving the issue.
Causes:
Document Deletion: The document may have been deleted or not created properly, leading to the absence of a document header.
Incorrect Document Number: The document number provided may be incorrect or does not exist in the system.
Data Inconsistency: There may be inconsistencies in the database, possibly due to a failed transaction or a system error.
Authorization Issues: The user may not have the necessary authorizations to view the document.
System Configuration: There may be configuration issues in the FI module that prevent the document from being recognized.
Solutions:
Verify Document Number: Check the document number you are trying to access. Ensure it is correct and exists Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
FI194 Online payment program: Residuals items without invoice ref. not allowed
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
FI193 Funds Management account assignment &/&/&/& does not exist
What causes this issue?  You want to post a document within a company code that is assigned to an FM area. This is not possible since you have not ent...
FI196 Invoices belonging to a residual item could not be found
What causes this issue?  You want to post a residual item without an invoice reference. This is not possible since payment matching is active in <L...
FI197 It is not possible to delete period-end closing and payments on account
What causes this issue?  You have selected payments without invoice references to be deleted on return. You have also activated period-end closing. Yo...
Click on this link to search all SAP messages.