because there are so many questions and confusion about the so called 'Pre-Approval' and because of the problems faced by applicants for the German work permit I attache a letter which could help you.
The German Consulates world wide ask for a letter from the Federal Employment Agency where it is stated that they have checked your job description, your employment contract and your degrees and that you are eligible for the German work permit. The problem is, that they do not check and do not give such a letter in case your yearly salary is above 53.600,- € ! The idea is, that someone who earns this much must be highly qualified and there is no need to do this extra work.
Some visa officers do not know this and insist on the letter.
I talked to the Federal Employment Agency and explained the problem. They answered that they know about this, but that they can not change it and I should contact the Foreign Office in Berlin, Department 508.
I do not expect fast results so I attache the letter they send to me, that you can print it and take it to the Consulate that you can show it to your visa officer. Maybe it helps..