Gst file not created

When the offline utility fails to generate the JSON file, the issue is almost always triggered by macro security blocks in Excel, formatting errors in date/invoice fields, or attempting to run the utility directly inside an unextracted ZIP folder. Extracting the offline utility to a local directory, clearing extra blank rows, ensuring dates follow the DD-MMM-YYYY format, and importing the Excel file through the GST Offline Desktop Application will eliminate the error and create the JSON file successfully.

I would first distinguish a file-generation error in the offline tool from an upload error on the GST portal. They need different checks; the question alone does not establish a portal defect.

If this is the GSTR-1 Returns Offline Tool, validate the entries and correct the fields flagged in red before generating the JSON. If a JSON was generated but the portal reports errors, download the error file, open it in the tool and correct the affected records. GSTN's Returns Offline Tool manual describes both steps.

Please share the return name, tool version and exact error message, with GSTIN and invoice/customer details masked. That should help identify the failing stage without exposing private data.

General information, not advice.