Issue in submitting JSON file in income tax portal

Uploading JSON File to GST Portal

1. Step 1 – Go to the Return Dashboard. Step 2: Select the month for which GST return is to be filed. ...
2. Step 2 – Select Prepare Offline. ...
3. Step 3 – Upload JSON file downloaded from LEDGERS. ...
4. Step 4 – Successful upload of JSON file to GSTN. ...
5. Step 5 – Uploaded invoices will be shown on GST portal.

I am a salaried employee and No GST for me. 

After preparing your ITR, you need to upload the prepared ITR JSON file using below mentioned steps:

• Visit the Income Tax Portal and login using valid credentials.
• Click on the e-File > Income Tax Returns > File Income Tax Return from the dashboard
• In order to file the return using the JSON file, the taxpayer needs to select the mode of filing as offline.
• Attach the JSON file
• In case there are no errors, the next screen would show you the message “Successful Validation“. Next, click on the “Proceed to Validation” option.
• Confirm the submission of the income tax return.
• Finally, you would receive the success message displaying the successful submission of the ITR. You will also receive an email along with the acknowledgment number and the ITR-V on the registered email ID.Submitting the ITR to the ITD is not the last step of the process. Submitting the ITR to the ITD is not the last step of the process. You still have to verify your return within 120 days of the submission of your return.

Facing exactly the same issue

Eventhough the gratuity received and exemptions are the same. 

Under the salary, split up the Basic Income also to Gratuity to see if the mapping works fine, but even then it gives the same error. 

Finally was able to overcome this error, by adding the Gratuity exemption by selecting 
"any other" and filling the descripttion.

Only thing ensure that the Utility is completely closed and reopened after this change. Otherwise it was giving me the validation error always as the error URL was not taking me to the right place.