rvk

YIKES. $474/year for a Code signing certificate ????? Shouldn't be any more than $100/Year or so via some Sectigo reseller. Examples here and here. You'll need a Code signing certificate ("SSL" EV won't do and I've never needed an EV Code certificate). I also never seen the icon disappear. What tool do you use to sign and what command line options?

Are you using a redirected scanner in WTS? Or is the scanner-software (and 64bit driver) directly installed on the WTS machine? Does the DelphiTwainDemo2 example work in WTS? Not sure what you mean by this? In Windows Terminal Services (now called Remote Desktop Services, RDS) you also just run plain applications, don't you? Or do you mean it's running under Windows Services? (which is hugely different)

Hard to say what could be the cause without example-source of DLL and calling procedure.

On 64 bit it worked for me but I did't have any scan-sources. WIA sources are 32-bit and not visible in 64 bit for me. Installing the VueScan gave me a 64 bit source. What Delphi version do you use? Are you using VLC of FMX? Did you try the DelphiTwain\examples\VCL2\DelphiTwainDemo2 example? (which worked for me on 64 bit)

So you provided a "bad value" Here it works fine with VueScan as 64 bit scan-sourcedriver. What/which scannerdriver did you try/use?

But that's how we recognize the administrators 😁 (although that information is also under the avatar-hoover.) I find that information useful to see in one glance. Hovering over the avatar hides it too much for me. +1 for the other suggestions although I wonder how much the layout can be changed from the default via themes (because this is based on standard forumsoftware). Ah well, there is always greasemonkey