Can't install my own ElasticSearch plugin

I've built my own ES plugin some time ago using ES 0.20.1. Worked fine. Today, i thought i would get back on that project and first try to redeploy it on the latest version (0.20.6) as i already did earlier getting from 0.19.8 to 0.20.1. So i updated the dependency to use the 0.20.6 lib, runned my tests (all passed) and built the plugin. (i'm using maven) That generated a file named `elasticsearch-MyPlugin-0.20.6.zip` wich contains the jar `myplugin-0.0.1-SNAPSHOT-jar-with-dependencies.jar` Then as usual i deploy my plugin using ``` sudo /usr/share/elasticsearch/bin/plugin -url /path/to/foler/containing/zipfile -install MyPlugin ``` That use to work... but it now throws me the following error: ``` -> Installing MyPlugin... Failed to install MyPlugin, reason: no protocol: /path/to/foler/containing/zipfile ``` So i fell back to what the ES documentation says about installing plugin. ``` sudo /usr/share/elasticsearch/bin/plugin -url file:///path/to/foler/containing/zipfile -install elasticsearch-MyPlugin-0.20.6 ``` Here's the output: ``` -> Installing elasticsearch-MyPlugin-0.20.6... Trying file:/path/to/foler/containing/zipfile... Downloading .DONE failed to extract plugin [/usr/share/elasticsearch/plugins/elasticsearch-MyPlugin-0.20.6.zip]: ZipException[error in opening zip file] ``` Just to be thorough, i have the file `es-plugin.properties` which points to the right class. I'm gessing there's a problem in the names i use and/or the way i install the plugin but i can't get my hands on what's wrong.