MultiInstance, bpm_JpqlQueryUserListProvider, simple query doesn't work


I have some troubles with getting user list for multiinstance user task, using bpm_JpqlQueryUserListProvider and jpql query.
The query is pretty simple:
“select u from suvvt_User u”
Screenshots of multiinstance settings:

When I start the process and go to this multiinstance user task, I’ve got the error:
“ClassCastException: class cannot be cast to class java.lang.String ( is in unnamed module of loader ‘app’; java.lang.String is in module java.base of loader ‘bootstrap’)”

So, what’s incorrect - query or smth else? How to fix it?

Hello Vadim, thank you for the report.

First of all, if you check java docs for io.jmix.bpm.provider.impl.JpqlQueryUserListProvider it says
Provided query should return usernames instead of users itself. So you should return from your query directly names of users.
But it does not cure the reported problem, currently we have the wrong generation for assignee expression in that case, I’ve raised the issue

Regards, Artem.