Unable to open es-419 projects even though Service Pack 2 is installed for Studio 2015

As the subject says, I cannot open projects, TMs, packages, with this es-419 language extension. Any opinion, comment and suggestion witll help me because I have been dealing a while with this and cannot find the answer.

I paste below the message I receive from the software.

Kind regards to all of you, and Happy New Year!

 

Error processing command line arguments: The language code 'es-419' is not supported on this system.

USAGE: SDLTradosStudio.exe [/help|/?] /arg1 val1 /arg2 val2

Task: NoAutoUpdate

Description: Starts the application without automatically checking for updates.

Usage: SDLTradosStudio.exe /noautoupdate

Arguments:

                /noautoupdate    Starts the application without automatically checking for updates.

Task: Open Retrofit

Description: Opens a retrofit file in the Alignment View.

Usage: SDLTradosStudio.exe /openRetrofit <retrofit>

Arguments:

                /openRetrofit       The full file path to the retrofit file you want to open.

Task: Open Alignment

Description: Opens an alignment in the Alignment View.

Usage: SDLTradosStudio.exe /openAlignment <alignment>

Arguments:

                /openAlignment  The full file path to the alignment you want to open.

Task: Create Project

Description: Starts the Create Project wizard.

Usage: SDLTradosStudio.exe /createProject [/files <file1> [<file2> <folder1> ...]] [/name <name>] [/template <template>] [/referenceProject <referenceProject>]

Arguments:

                /createProject     Starts the Create Project wizard.

                /files       The full file path of one or more documents or folders to add to the Create Project wizard.

                /name    The name of the Project

                /template              An existing template name or file path to use.

                /referenceProject              An existing reference project file path to use.

Task: Open Document

Description: Opens a document or a number of documents in the Editor View.

Usage: SDLTradosStudio.exe /openDocument <document1> [<document2> ...]

Arguments:

                /openDocument  The full file path of one or more documents to open.

Task: Open File Based TM

Description: Opens a file based TM or a number of file based TMs in the TM View.

Usage: SDLTradosStudio.exe /openFileTm <file tm1> [<file tm2> ...]

Arguments:

                /openFileTm         The full file path of one or more TMs to open.

Task: Open Package

Description: Opens a package in the Package View.

Usage: SDLTradosStudio.exe /openPackage <package>

Arguments:

                /openPackage      The full file path of the package to open.

Task: Open Project

Description: Opens a project in the Projects View.

Usage: SDLTradosStudio.exe /openProject <project>

Arguments:

                /openProject       The full file path of a Project to open.

Task: Open Server Project

Description: Opens a server project in the Projects View.

Usage: SDLTradosStudio.exe /openServerProject <project URI>

Arguments:

                /openServerProject           The URI of a Server Project to open.