i'm getting a "please try a different zip archive" issue now, on a mac running osx 10.12.6.
my current bela version says it's 0.2.1, August 2017.
trying to update to the latest (non experimental)
Can you retry and report all the text printed before "please try a different zip archive" ?
Also, run cat /root/update.log in the IDE console and return its content, please.
Incidentally, unless you have a major reason to stick with the 0.2.1 image, I'd recommend you update to the 0.3.4 which we are going to release tomorrow. This involves flashing your SD card using this procedure (https://github.com/BelaPlatform/Bela/wiki/Manage-your-SD-card#flashing-an-sd-card).