Nand Erase and Bad CRC error for VF50 modules

Problem 1)
While performing production programming of VF50 module serial no 08406732. Once uboot is loaded, pressed space at uboot menu, and issue command nand erase.part ubi we are getting below error:

NAND erase.part: device 0 offset 0x200000, size 0x7e00000
Skipping bad block at  0x013c0000                                          
Skipping bad block at  0x07f80000                                          
Skipping bad block at  0x07fa0000                                          
Skipping bad block at  0x07fc0000                                          
Skipping bad block at  0x07fe0000                                          

See attached file 08406732.txt for more deatils.

Problem 2)
At uboot for module serial number 08407182 we are getting below error.
VF50 Serial number 08407182 has below CRC warning:

*** Warning - bad CRC, using default environment

Please find attached 08407182.txt file for more details.

We tried erasing nand as suggested on below two links for above two problems but still problem persists:

and

About 10 new boards are shown this nand erase problem and Bad CRC problem.

Hi @amolyp

Could you provide the version of the Hardware and software of your module? Are these modules still booting?

Hello @amolyp

Problem 1 While performing production programming of VF50 module serial no 08406732. Once uboot is loaded, pressed space at uboot menu, and issue command nand erase.part ubi we are getting below error

Bad block on NAND flash are something normal. You can just install the image and the module should work.

Problem 2 At uboot for module serial number 08407182 we are getting below error. VF50 Serial number 08407182 has below CRC warning:

This is a simple warning which can be corrected by following this.