Upgrading to UPM in Stash 3.2 results in com.atlassian.upm.api.util.Option$3 cannot be cast to com.atlassian.upm.api.util.Option

Updating Universal Plugin Manager to version 2.17.10 in Stash 3.2.0 and 3.2.2 will make the Manage Add-Ons page not to work and display com.atlassian.upm.api.util.Option$3 cannot be cast to com.atlassian.upm.api.util.Option.

Workaround
Restarting Stash instance will aid this problem.