gstr 4 inward supplier from reg. error dates

GST Utility are prepared on basis of English (India). So you need to select the date format according to "English (India)" in "Format Cell" Option of Excel and than you will get the date in correct format as per GST Tool. Now try to validate file.

If u face still same problem u can blank in the part of inward purchase because it is  not compulsory still now for GSTR4