Message type: E = Error
Message class:  FKK_ID_PT_SIGN - Digital Signature Portugal FI-CA/IS 
Message number: 601
Message text: Document & cannot be printed since preceeding documents are not signed
The system cannot proceed with the printing of the  document because
there are too many  unsigned documents for this number range.
To avoid performance issues, the system does not trigger the creation of
digital signatures for existing unsigned documents. The printing of the
requested document cannot be created because digital signature data is
not available.
Run the report to create digital signatures for unsigned documents.
Depending on your system settings, this occurs automatically, or you
need to run the report manually.
Trigger the report to create digital signatures.
You should check the reason why there are too many unsigned documents.
Check if a different number range assignment in event 1190 can avoid
this error. Hint: Documents for postings  that need to be printed out
immediatly (e.g. cash desk) require a separated number range.
Error message extract from SAP system. Copyright SAP SE.
The SAP error message FKK_ID_PT_SIGN601 indicates that a document cannot be printed because it has preceding documents that have not been signed. This is typically related to the SAP Convergent Charging or SAP Contract Accounts Receivable and Payable (FI-CA) modules, where document signing is a requirement for processing.
Cause: Missing Signatures: The document you are trying to print has one or more preceding documents (like invoices, credit memos, etc.) that have not been signed. In many business processes, documents must be signed in a specific order before subsequent documents can be processed or printed. Workflow Issues: There may be a workflow in place that requires certain approvals or signatures before a document can be finalized. Configuration Settings: The system may be configured to enforce document signing, and if the preceding documents are not signed, it will prevent printing of the current document.
Solution: Check Preceding Documents: Review the preceding documents related to the one you are
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