Blood Glucose Watch Face by Dududu13 crashing

I have the watch face Blood Glucose by Dududu13 on my Garmin Fenix 6x Saphire. I really like the layout and options and it does read my XDrip glucose and display correctly. 

The only problem is that it crashes and defaults back to the original Default Fenix Watch face. 

The app hasn't been updated for a few years and I haven't been able to contact the developer. 

Does anyone else have any experience with this watch face and have a possible solution.