No prescan with demo of SilverFast Ai Studio 8.5

[dsf]

I got the demo version of Ai Studio 8.5, installed it on an iMac with a Pacific Images PowerSlide 5000 scanner. It works for the most part, but clicking the Prescan button does nothing. Well, it says it is prescanning, but nothing happens and no image comes up. The final scan works. Is this a known problem for this device? Is it related to the use of the demo version? Could it be a hardware problem in my scanner?

[LSI_Ketelhohn]

Dear customer,

Please make sure that the latest firmware is installed on your scanner.
The behaviour you describe often occurs with outdated firmwares.
The firmware (a 64kb .bin file) can be downloaded from the manufacturer website and uploaded to the scanner through the CyberView "Help" menu.

Kind regards,
Arne Ketelhohn.