2012 Prius v stuck in software update mode

I don't think they can fix the upper limit for our models, maybe next generation of Prii.

 

THANK YOU!!! For sharing your experience and solution. I was searching to fix the bluetooth issue (unable to stream spotify, podcast, youtube, other audio) on a 2015 Prius Five with navi.
I, too, used a newer (usb 3.0) 32gb stick which looped my system. I also went through 3 usbs myself lol
Some added info if it helps: I upgraded from Entune version 2.1 to 5.2 (latest) and I am using an iPhone 7 on iOs 12.2

I hope others find this post as it was a life saver!!

 

Thank you, this thread very help me! Same problem, but solved.
How solved:

I have Toyota Touch&Go.
1. Transfer Prius System information data to formated 8 GB USB stick Kingston Data Traveller.
2. Backup data to PC!!!
3. Download Toyota Toolbox (Windows). Buy new maps €119.
4. Transfer new software and maps to 8 GB stick Kingston Data Traveller by Toolbox.
5. Backup data to PC!!!
6. Insert 8 GB stick to Prius, start engine to "READY". Update automatic starting,
7. Map selection -> update working,
8. Update FAIL! "Insert valid USB stick...", you know...
9. Take new (used) USB noname stick 16 GB. Format (long).
10. Copy files from old (fail) 8 GB stick to "new" 16 GB (alternatively use 2nd backup). No use Toolbox, just standard copy files from "old" to "new" clean USB stick.
11. Prius power off. Insert new 16 GB noname stick. Prius power on, engine "READY". Update start automatic approx. 40 min.
Done.

New sw version: 2.19.0WL
"New" maps version: EUL20181116 (maps from Septenber 2018 in October 2019, this is joke, Toyota???)

Problem solved.