Message type: E = Error
Message class:  ICC_NF_WRITER - Messages for Nota Fiscal Writer, Numbering and Printing 
Message number: 014
Message text: CFOP code cannot be changed; import document data exists for NF item &1
Import document data exists for this NF item. You changed the CFOP code
for this NF item and now the code is not allowed for imports (code must
start with 3).
You cannot save the nota fiscal until you delete the import document
data for this NF item.
Open the <LS>Nota Fiscal Writer</> by calling the <ZH>J1B2N</>
transaction.
Select the <LS>Import Documents</> tab page.
Delete the import data for this NF item.
Save your changes.
The system issues an error message and will not allow you to continue with this transaction until the error is resolved.
Error message extract from SAP system. Copyright SAP SE.
The SAP error message ICC_NF_WRITER014 indicates that there is an issue with changing the CFOP (Código Fiscal de Operação e Prestações) code for a specific NF (Nota Fiscal) item because there is already existing import document data associated with that item. This typically occurs in the context of Brazilian tax compliance, where CFOP codes are used to classify the nature of the transaction.
Cause: The error arises when you attempt to modify the CFOP code for an NF item that has already been processed or has existing import data linked to it. This is a safeguard to prevent inconsistencies in tax reporting and compliance, as changing the CFOP could affect how the transaction is reported to tax authorities.
Solution: To resolve this error, you can consider the following steps: Review the NF Item: Check the NF item in question to understand its current CFOP code and the associated import document data. Ensure that you have
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
ICC_NF_WRITER013 For NF item &1 enter a CFOP code for imports (starts with 3)
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
ICC_NF_WRITER012 Enter NF item number for addition no. &1/add. item &2
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
ICC_NF_WRITER015 Selected MS Excel file cannot be uploaded; file path incorrect
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
ICC_NF_WRITER016 Enter a value for end row that is equal to/greater than start row
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.