When i choose a picture and i go from 'library' to 'development' to edit the picture then something goes wrong.
In 'development' there is a dark haze over the picture (the picture gets darker).
This problem is only on my iMac and not on my macbook. (I use LR for years now and never had this problem before).
Can somebody help me, because i can't edit with this problem.
This is usually caused by a defective monitor profile.
As a diagnostic step and possibly a temporary fix, try setting the monitor profile to sRGB, as described here:
If this fixes the issue, you should ideally calibrate your monitor with a hardware calibrator, which will create a new, correct profile.
If it doesn't fix the issue, please post a screenshot showing Library and Develop for the same image.
Thank you very much Per!! Problem solved