Crashplan on Duo/NV+ v2? [SOLVED + TUTORIAL]

I'm trying to follow the tutorial kindly posted by filzip77 a few years ago, but unsurprisingly things seem to have moved on since then. The current version of CrashPlan seems to be 3.6.3. I've been able to follow the steps as far as running the install.sh script inside the CrashPlan-install folder (incidentally I found I needed to reverse the order of the arguments in the ln command to get the correct result; I had to type "ln -s /c/home/daniel/ejre1.7.0_51 /usr/java/j2se" to get the appropriate symbolic link), but when I do I get the following output:

Welcome to the CrashPlan Installer.

Press enter to continue with installation. 

Validating environment...
  detected root permissions
No Java VM could be found in your path
Would you like to download the JRE and dedicate it to CrashPlan? (y/n) [y] n

We're sorry, CrashPlan requires a valid Sun JRE or OpenJDK. Please install one and then
rerun this installer. Exiting.

If I type env, I see both JAVA_HOME and PATH set correctly as per filzip77's tutorial, so on the face of it everything should be okay. Does anybody have any idea what's going wrong and what I might try next?

Thanks!

Daniel