This problem has affected my two Synology America DiskStation 2-Bay Diskless Network Attached Storage (DS214play). The solution I ended up finding Here the chrisnelson.ca and worked with a small adaptation in the command syntax unzip, adding the quotes.
The solution that worked for me was to connect the Synology via SSH, logando as root (same administrator password) and use the following commands to extract the update screwed:
unzip -o /var/packages/CrashPlan/target/upgrade/1425276000420.jar "*.jar" -d /var/packages/CrashPlan/target/lib/
unzip -o /var/packages/CrashPlan/target/upgrade/1425276000420.jar "lang/*" -d /var/packages/CrashPlan/target/
After, you must use the command ls to see what is the specific path of your installation to then use the second command below:
ls -l /var/packages/CrashPlan/target/upgrade/1425276000420.*
mv /var/packages/CrashPlan/target/upgrade/1425276000420.numeroobtidoacima/upgrade.sh /var/packages/CrashPlan/target/upgrade/1425276000420.numeroobtidoacima/upgrade.sh.old
Then just start Crashplan the package and check the log if everything went right.