Just the page lead detailview blocked

Hello i use version 8.1.1, the page /leads/index?return_module=Leads&return_action=DetailView is very very slow, blocked page, Can anyone help me solve it?

Any reason why not upgrade to current version 8.4.2 ?

Chris I tried yesterday all night but I couldn’t.
I can’t understand what I’m doing wrong!!

my space has this extension; home/user/public_html (root) / public / …
In public_html have create folder: /tmp/package/upgrade
in upgrade I inserted both the zip and decompressed file SuiteCRM-8.2.0.zip
return in pubblic html - ./bin/console suitecrm:app:upgrade -t SuiteCRM-8.2.0
error. permission denied

thank you

Can you try to reproduce your issue on the online demo for 8.4.2 ?