can't edit individual record

can't edit individual record

Hi all,

For some obscure reason, I can't edit individually any record from my main list view anymore.
The black loading screen appears, with the "Please Wait..." message, but the more I wait the less anything happens. Editing form simply never appears.

Strangely enough, I'm able to "bulk edit" records (including records one by one). The form is also slow to load, but it works.

Any suggestions?

Cheers,
D_