Using RUI requires zip to be uploaded to build.rakwireless.com.
However, using macOS compression will add .DS_Store file. This will result to failure on RUI compilation since .DS_Store should not be on your uploaded zip file.
To avoid this (instead of doing the default way of right-clicking on the folder and select compress to generate zip file), you must use a different approach.
My method is via terminal. Open the terminal and go to the directory where your RUI source code folder is located then you can generate your zip file without .DS_Store by running the command below.
zip -r RAK4600.zip RAK4600 -x "*.DS_Store"
RAK4600 is the folder name of your RUI source files and it will generate a RAK4600.zip which is now ready for the RUI Online compiler.