True ! So I contacted the support by mail and get an answer really quickly. According to this answer I think I will keep my Java up to date with original settings and will only use their software “WD My Cloud Desktop utility”.
See the answer below:
"Thank you for contacting Western Digital Customer Service and Support.
We apologize for this inconvenience. According to this behavior, the issue is related to the security settings integrated on the Java update. We would recommend testing a different browser or running a previous version of Java. Also, lowering the security settings of Java to Medium will allow the shares to be accessible on all browsers.
However, our best recommendation is downloading the WD My Cloud Desktop utility. This application does not require Java and has no restriction on file transfer size for a better performance. You can download it at:
http://support.wd.com/product/download.asp?groupid=904&sid=209&lang=en
If needed, you can also add the URLs to the exception site list on the security settings of Java update 51. Please find below a link with the information on how to complete the process. For additional details or instructions, we strongly recommend contacting Oracle:
http://www.java.com/en/download/help/java_blocked.xml
If you have any further questions, please reply to this email and we will be happy to assist you further."
