ADE 4.5.12 does not work anymore

I use ade 4.5.12 to load EPUB/ .acsm files, on a PC with Windows 11, updated. In the last few days ADE refuses to accept .acsm files downloaded to my computer. When I try to transfer a file to ADE, the transfer seems to start, but very slowly, and 1-2 minutes later appears an error box with the error code E_STREAM_ERROR. Then ADE stops responding and I have to use Task Manager to close it.

I have uninstalled the program from my computer, I have cleared  \HKEY_CURRENT_USER\Software\Adobe\Adept in the Registry. I have downloaded a new version of the program and re-installed it. I have authorized ADE.

Same problem: ADE does not accept .acsm files.

Can you help?