Android Studio 3, building release --min-sdk-version - release

Question

I updated to Android Studio 3. I can build the "debug" apk but now I cannot build the "release" apk. I get this error:
:app:transformClassesWithPreDexForRelease FAILED
AGPBI: {"kind":"error","text":"unknown option: --min-sdk-version","sources":[{}]}
AGPBI: {"kind":"error","text":"usage:","sources":[{}]}
AGPBI: {"kind":"error","text":" dx --dex [--debug] [--verbose] [--positions\u003d\u003cstyle\u003e] [--no-locals]","sources":[{}]}
AGPBI: {"kind":"error","text":" [--no-optimize] [--statistics] [--[no-]optimize-list\u003d\u003cfile\u003e] [--no-strict]","sources":[{}]}
AGPBI: {"kind":"error","text":" [--keep-classes] [--output\u003d\u003cfile\u003e] [--dump-to\u003d\u003cfile\u003e] [--dump-width\u003d\u003cn\u003e]","sources":[{}]}
AGPBI: {"kind":"error","text":" [--dump-method\u003d\u003cname\u003e[*]] [--verbose-dump] [--no-files] [--core-library]","sources":[{}]}
AGPBI: {"kind":"error","text":" [--num-threads\u003d\u003cn\u003e] [--incremental] [--force-jumbo] [--no-warning]","sources":[{}]}
AGPBI: {"kind":"error","text":" [--multi-dex [--main-dex-list\u003d\u003cfile\u003e [--minimal-main-dex]]","sources":[{}]}
AGPBI: {"kind":"error","text":" [--input-list\u003d\u003cfile\u003e]","sources":[{}]}
AGPBI: {"kind":"error","text":" [\u003cfile\u003e.class | \u003cfile\u003e.{zip,jar,apk} | \u003cdirectory\u003e] ...","sources":[{}]}
AGPBI: {"kind":"error","text":" Convert a set of classfiles into a dex file, optionally embedded in a","sources":[{}]}
AGPBI: {"kind":"error","text":" jar/zip. Output name must end with one of: .dex .jar .zip .apk or be a directory.","sources":[{}]}
AGPBI: {"kind":"error","text":" Positions options: none, important, lines.","sources":[{}]}
AGPBI: {"kind":"error","text":" --multi-dex: allows to generate several dex files if needed. This option is ","sources":[{}]}
AGPBI: {"kind":"error","text":" exclusive with --incremental, causes --num-threads to be ignored and only","sources":[{}]}
AGPBI: {"kind":"error","text":" supports folder or archive output.","sources":[{}]}
AGPBI: {"kind":"error","text":" --main-dex-list\u003d\u003cfile\u003e: \u003cfile\u003e is a list of class file names, classes defined by","sources":[{}]}
AGPBI: {"kind":"error","text":" those class files are put in classes.dex.","sources":[{}]}
AGPBI: {"kind":"error","text":" --minimal-main-dex: only classes selected by --main-dex-list are to be put in","sources":[{}]}
AGPBI: {"kind":"error","text":" the main dex.","sources":[{}]}
AGPBI: {"kind":"error","text":" --input-list: \u003cfile\u003e is a list of inputs.","sources":[{}]}
AGPBI: {"kind":"error","text":" Each line in \u003cfile\u003e must end with one of: .class .jar .zip .apk or be a directory.","sources":[{}]}
AGPBI: {"kind":"error","text":" dx --annotool --annotation\u003d\u003cclass\u003e [--element\u003d\u003celement types\u003e]","sources":[{}]}
AGPBI: {"kind":"error","text":" [--print\u003d\u003cprint types\u003e]","sources":[{}]}
AGPBI: {"kind":"error","text":" dx --dump [--debug] [--strict] [--bytes] [--optimize]","sources":[{}]}
AGPBI: {"kind":"error","text":" [--basic-blocks | --rop-blocks | --ssa-blocks | --dot] [--ssa-step\u003d\u003cstep\u003e]","sources":[{}]}
AGPBI: {"kind":"error","text":" [--width\u003d\u003cn\u003e] [\u003cfile\u003e.class | \u003cfile\u003e.txt] ...","sources":[{}]}
AGPBI: {"kind":"error","text":" Dump classfiles, or transformations thereof, in a human-oriented format.","sources":[{}]}
AGPBI: {"kind":"error","text":" dx --find-usages \u003cfile.dex\u003e \u003cdeclaring type\u003e \u003cmember\u003e","sources":[{}]}
AGPBI: {"kind":"error","text":" Find references and declarations to a field or method.","sources":[{}]}
AGPBI: {"kind":"error","text":" declaring type: a class name in internal form, like Ljava/lang/Object;","sources":[{}]}
AGPBI: {"kind":"error","text":" member: a field or method name, like hashCode","sources":[{}]}
AGPBI: {"kind":"error","text":" dx -J\u003coption\u003e ... \u003carguments, in one of the above forms\u003e","sources":[{}]}
AGPBI: {"kind":"error","text":" Pass VM-specific options to the virtual machine that runs dx.","sources":[{}]}
AGPBI: {"kind":"error","text":" dx --version","sources":[{}]}
AGPBI: {"kind":"error","text":" Print the version of this tool (1.11).","sources":[{}]}
AGPBI: {"kind":"error","text":" dx --help","sources":[{}]}
AGPBI: {"kind":"error","text":" Print this message.","sources":[{}]}
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:transformClassesWithPreDexForRelease'.
> com.android.build.api.transform.TransformException: java.lang.RuntimeException: java.lang.RuntimeException: Unable to pre-dex 'C:\Users\Prueba\.gradle\caches\transforms-1\files-1.1\play-services-ads-11.8.0.aar\65e20ddd21f188b13248bf1ecfe51ae0\jars\classes.jar' to 'C:\Android\Workspace\MyApp\app\build\intermediates\transforms\preDex\release\3.jar'
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
* Get more help at https://help.gradle.org

Answer 1

I updated buildToolsVersion to "27.0.1" in the Gradle and everything started to work again.
android {
...
buildToolsVersion "27.0.1"
...
}