So I just had a chat with HTC are exoeriencing this exact issue a couple times and their solution of Wiping the phone's cache seems to have resolved it, feel free to reach out to them or read the steps below:
1) You can wipe the cache partition on the phone. This will resolve the error.
2) First, please enter ALL APPS > SETTINGS > POWER
3) Great. Uncheck the options for FASTBOOT if it is active
4) Once FASTBOOT has been disabled, please power off your phone.
5) Kindly press and hold the VOLUME DOWN and briefly press the POWER button while holding the VOLUME DOWN.
6) You should see a special screen with some options.
7) Use the volume keys to highlight Recovery and press Power to select it. The screen will load to an image of a red triangle with an exclamation point.
8) Once you see that screen, Press Volume Up and Power at the same time to show the Recovery Menu.
9) Once you press VOLUME Up and Power to enter the recovery menu, Use volume keys to highlight “wipe cache partition” then press Power to select. This may take approximately 30 seconds depending on the amount of information it has to go through. When done, highlight the option to reboot/restart phone and again press Power to select please.
10) Try the FM Radio app on your phone, this should resolve your issue.