What error? You still haven’t told us. Please stop wasting helpful volunteer’s time running around in circles. No one can help you until you provide the information you’ve already been asked for.
This thread is unlisted (publicly hidden) for now. You’ve already received an official warning and have had a previous suspension. Take one step over the line your account will be suspended until the end of time. No more warnings.
Had this error few minutes ago. The error solved itself. Seems like Flatpak was to blame. It was downloading its own stuff and the users (including me) were impatient. I searched for a package on terminal and it took more than 8 hours to give me a result. But after that, Add/remove software opens and works fine for me. I have pretty good fiber connection but according to System Monitor, Flatpak was talking less than 100KBps internet speed. So definitely Flatpak to blame here.