I am trying to flash the STM32F429ZI with j-Link, however, the application is not getting flashed with an exception saying unspecified error.

[ANalg.1]

Basically, I want to view the RTT logs & that's why I am programming it via j-link. (I had ST-Link on board, but as RTT viewer is not supporting with ST-link, I had to convert ST-link into j-link). 

[Uwe Bonnes]

Try other tools that can use JLINK (OpenOCD, BMP hosted) or flash back STLINK to try to get a better error output.