This is my dependencies file and there is an underlined red colored text on the compile \'com.android.support:appcompat-v7.27.1.1\'
apply plugin: \'com.andr
just goto-> files->project structures->app->flavors change your min SDK version and target SDK version to "API 27:" then go to properties and check that your compile SDK version has also changed to the above version which you selected.
This worked for me.