Check out example codes for "E/flutter (20384): [ERROR:flutter/third_party/txt/src/minikin/FontFamily.cpp(184)] Could not get cmap table size! E/flutter (20384): F/flutter (20384): [FATAL:flutter/third_party/txt/src/minikin/FontCollection.cpp(95)] nTypefaces == 0". It will help you in understanding the concepts better.
Code Example 1
In my case I deleted the .ttf file and readded them and deleted lines reg regarding font family in pubspace.yaml file and flutter-clean the project and again add the lines with internet connection while Packages get
Learn ReactJs, React Native from akashmittal.com