Hello, Jean-Noel
Yes, there was a bug in CVI 6.0 through 8.0, which prevented string controls from being downsized when their font size was reduced, as a result of scaling. The fix for this will be included in CVI 8.0.1.
I'm not really sure why you're getting the ActiveX error, but my guess is that it wasn't installed properly. It might not be sufficient to simply distribute the DLL, since that DLL might depend on other components. The only safe way would be to include an actual installer (an .msm, or .msi), if you have one.
Having said that, you have a much simpler alternative to the ActiveX control. The problem with the CVI string control does not exist in the classic-style version of the control. You can simply use this one instead (you can find the Classic-Style controls at the bottom of the control palette).
Luis
NI