Why is the D9Viewer called D8Viewer.exe ?
That´s only the name, from back of the days, where Directory Opus 8 was introduced, i suppose The internal version number is 10.0.0.2, just like the current version.
The problem is the registry idenitifies it as D9viewer as the handler for JPG on my system ... it is diappointing that the name doesn't correspond to the actual filename.
Looking into Opus´ file type dialog here, i have only the "Directory Opus Viewer" handling the JPGs. So if you say registry, do you try to approach in a specific way?
Don´t the JPGs open correctly in the viewer? A quick search trough my registry shows several hits for d8Viewer, but none für d9viewer.
Mime control as set by the registry
If it got renamed with every version change it would breaks anything that referred to it.
In hindsight, it should not have had a number in its name at all, but it is just a number.