Hi turminator,
I had a similar problem with italian language and I solved it.
Try as folow:
1) In zipped file, modify the file spanish.xml the row <version>1.2</version> with <version>1.2 RC 4</version>
2) Don't install the plug-in by classical mode but by 'plugin management' in Components/community builder menu
I hope it usefull.
Bye,
infinito1971