Active topics - seen only with login?

[modelsof1900]

Hallo admins,
I have a prpbem since a few days, maybe two or three weeks.
My standard bookmark for Big Blue is saved as search on "View aktive topics" and regulerly I'm not logged in when I use this bookmark for a fast view on new or changed topics. And so Big Blue was working all the times where I’m a member.
Since two or three weeks now I receive with identic conditions the answer “Sorry but you are not permitted to use the search system.” The reason is that I’m not logged in at this moment! After a login the search for active topics works again like all times before. However I would not be constrained to log in in order to see these active topics and I'm not lucky with the system in this present form!
Please let my know if this change is your intention or is this a small bug only together with another change of system?
I would be lucky if the old condition would be installed again, please.
And thanks for your answer!