Is there anyone who knows how to solve this error or can help?
You will have to modify your plugin file for the specific warning and point it to the local path of your project plugin.
Otherwise duplicate your plugin IWAS in the engine source folder but am not sure if that will work, you will need to trial and error for the correct path.
Having special characters and space in a path during packaging might cause issues as well but it most likely these path plugin that preventing you from packaging.