'Failed to Remove Permission'

I’m trying to remove permission of some user but it shows error ‘Failed to Remove permissions’ in that case what to do ?

@apiped_cohort, are you the admin/owner of the project, or was it shared with you by someone else? Could you also let us know which server you are using?

Thankyou @Kal_Lam for the response. yes i’m admin of the project. we are using professional version of kobo cloud server.

@apiped_cohort, are you on a public KoboToolbox server, or are you using a private server?