Cannot clear new members

My other Administrator is having problems clearing new members from her E-Mail. Each time she try to clear a new member she receives this message.

The text is circled in Yellow, thanks for any help in advance.

Ask her to clear her browser's cache and history.

She has done that an still it does not work, I am now having the same issue, I have cleared my Cache and still unable to clear new members. I can clear them manually, is there something I am missing something different to get us able to clear new members through e-mail again.

They have to just log in to the forum and then go to the following page

ACP >> Users & Groups >> Users >> Inactive Users

you can't just use the code to do it as you need to be logged in to make the change on the account.