In what software did you get repetitive message to update platforms?

When you submit reports its easier of you switch on vmicro>compiler>verbose and "show build properties". Then try to build and post the output as .txt

The verbose output and build properties show exactly what the compiler is trying to do and removes the darkness.

Verbose output should be attached as a .txt file to a post or email to info[at]visualmicro.com with a link to the relevant post such as this one.

It's not practical to edit arduino platform.txt without using verbose to check what you have done.

Normally it is hoped that people also give ide versions and arduino hardware board manager core versions otherwise I and other have no idea about which core you are using or expecting to make work.

If you make changes to core files for your own projects you should back up your changes and make a note of what you do so you can repeat it if you overwrite with updates.

Once you are able to describe the changes you want to make to the arduino core I might be able to suggest a better or more bullet poof alternative.