There is issue with gradle and I guess that it is possibly due to fact that gradle creates so long names e.g.:
I can see issue with bootRun task that application was not possible to start after I have changed a gradle user home dir it seems there is no issue.
As seems that it is not possible to change that in "preferences of Netbeans" in this version so only possibility is to change it via system environment variables:
- batch file for run netbeans
In any case both options are not so good.
My suggestion here is to add that as option for netbeans similarly as option "--cachedir"
like "--gradleUserHome "