DSpace 8 Error when saving item authorization policy

[RICARDO EITO]

Hi,

as a community and collection manager I want other user to be able of editing one item of my collection.

I understand that the Edit item > Status > Edit item's authorization policies > Authorizations should give the capability to do that.

I have tried to add a new policy to give WRITE permissions to the other user but when saving, it fails and I get an error. 

I can do the change only if I login as a DSpace Administrator, but not when I log as a community / collection manager.

Is this a constraint of DSpace permissions or something needs to be done in a different way?

thanks in advance.