Problems migrating game from 3.5 to 4.2

[brehiner]

All my game is made with this addon and I have so many shapes. In the proccess of migrate my game I have to delete the addon and back to install it but now show many errors similar to this: E 0:00:00:0524 _parse_ext_resource: res://prefabs/GUI/main.tscn:49 - Parse Error: [ext_resource] referenced non-existent resource at: res://addons/rmsmartshape/assets/GUI_Theme.tres <C++ Source> scene/resources/resource_format_text.cpp:163 @ _parse_ext_resource().

This is another erro: E 0:00:01:0713 start.gd:26 @ _on_Button_pressed(): Compressed texture file is corrupt (Bad header). <C++ Error> Method/function failed. Returning: ERR_FILE_CORRUPT <C++ Source> scene/resources/compressed_texture.cpp:46 @ _load_data() <Stack Trace> start.gd:26 @ _on_Button_pressed().

So I copie the file GUI_Theme.tres from old version but still there are many errors