I use a 4k monitor. In Vegas Preferences, I disabled the use of high DPI. In the properties of Vegas17.exe I have opened the compatibility mode, selected Change High DPI Settings, then activated the option "Program DPI" and set the value to 200% via "Open Advanced scaling settings". After restarting Vegas, not only the Otterbar is finally visible in acceptable resolution, but also the icons for Otterbar and Vegasaur are visible again, without me having to switch down to 1920x1080, or bring the system-wide scaling to less or equal 125% at 3840x2160.
I really wish the "high dpi" feature were off by default. I almost gave up on upgrading from 15 to 17 because on my multi-monitor setup I couldn't use both monitors because the fonts in the dialogs on my lower-res monitor were so HUGE