Why am I getting an error message when my Whatsapp is trying to loading?

I have a BB9720. I recently deleted my WA app and tried to reload it again. It starts loading, sometimes up to about 99% and then it bombs out. I got an error message that reads "The "RIM-COD-Size-29" attribute is missing. Error: Invalid manifest or application descriptor."

I have tried installing from BB World as well as direct from the WA site. Same problem. I have reset my phone back to factory settings and that hasn't helped either. Tried the "alt LGLG" thing too.

I am NOT tech savvy, could anyone pleeeease help with step by step instructions on how I could possibly fix this? Or should I take it for someone to look at?

sometimes a legacy device can have corrupted underlaying OS, please reload your OS using PC

you need to follow the directions in THAT forum post about whatsApp on BBOS 7
https://forums.crackberry.com/blackb...ended-1115275/

it's basically going to have you remove the app all together, then download it again directly from whatsapp.com/ota then change your date back to 2015, register your phone on the app and switch the date back and BLAMO. You have whatsapp until the end of the year.