I'm starting this thread to capture abnormal behavior (i.e. "bugs"😉 that have been observed after upgrading firmware to v12.
Please tell which version of N97 you have and how much C: drive space is available.
RM-507 (N97 NAM white) - 40.4 MB on C: drive
1. Messaging application
When trying to download and open a very large HTML email with .xls attachment (total size 1.67 MB), the email application seemed to hang and then the display went "rainbow", faded out and the N97 rebooted.
Open applications: Accuweather and Facebook.
2. Web Application
Occasionally I will start the Web browser and it will open briefly and then exit on its own. It may do this two or three times in succession before it opens properly and stays open.
....keeping my fingers crossed for v13!