FR645m can't load fonts: System Error

FR645m fails to load fonts despite it works in a simulator and other watches with the same resolution. 

ERA shows the next error: 

Error Name: System Error
Devices:
Forerunner® 645 Music: 7.20
Languages: deu, dut, eng
Backtrace:
lateView.setLayoutVars:470
lateView.loadSettings:309
lateView.onLayout:100

Triggered at this line of code and related fonts 

Happens right after the start-up and the app immediately fails. 

Only one user reported that so far. 

Any ideas how such thing could happen when any other watch works perfectly at such basic operation like loading fonts?