So I saw this error in v15 beta and it is still present in v15 RC although it seems to be 'reduced' if that makes sense. The error message is smaller in the RC than what was present in the beta. This is when clicking on 'Voicemail' under 'Settings' Closing that window lets me access the voicemail settings. Also, the button under settings is labeled 'Voicemail. but the title of the window is 'Voice Mail Settings'. I imagine it should be consistent, so probably 'Voicemail Settings'