This is just a notice, and you can ignore it. To properly fix it in B4A, B4j, or B4R, Update or Upgrade B4i to the latest version, which will be the same as the version used to create the File, and the warning will go.
Sledgehammer: Make a backup of your project, then open the *.b4a or*.b4i file in Notepad,
You will see the version in the header section, maybe B4A you will see version = 14.00, Change it to the version you have on your computer, and the warning will go.

REMEMBER to make backup first, so that if your source code corrupts, you will have a copy