EX3200/EX4200 switches running Jloader version of March 2013 are susceptible to uboot environment corruption during reboot.
Following version of Jloader can be applied to EX3200/EX4200 switches susceptible to this issue .The below version of Jloader does not exhibit this problem . Jloader Image : Image Name: jloader-ex-3242-12.1R3-signed.tgz Identifier : U-Boot 1.1.6 (Jul 5 2012 - 11:58:22) 1.0.0 Please use below links to download the Jloader image
2018/06/14 : Recover broken download links