OK, things seem fine again. A picture in the Nikon Capture Window looks the same as after the output in Photoshop, so does Capture One Pro, and even a jpeg in sRGB from C1pro looks the same as a tiff in Adobe RGB from the same raw converter.
Also C1pro works again. No more error messages.
Here's what I did:
The name of the monitor-profile is now 14 characters long instead of 26 as before.
In Spectraview Profiler 4.1.1 I chose the following options, not knowing in all cases what it means:
Type: Matrix Profile (formerly Table Profile)
Adaption: linear Bradford (formerly CAT02)
ICC v4 Profile unchecked (formerly checked)
I do not know which of these changements make my applications display consistent colors again and I hope my clients, which are mostly magazines, still see the same colors and contrast I intend here, but Iīm happy my problems seem to be solved now.
Thanks for you help,