Replacing or adding of tyres is not possible anymore

[vetbiker]

Hi all, some time ago I changed the tyres of the Ford Escort Mk 1 RS 1600 from Kunos to Tatus slicks soft/medium/hard. It was only for myself and not for use in online races, as I have this exact car in real and drive all races with slicks and it gave a very good feeling for tracks I have never been before. Not long ago I had some errors and had to reload AC from steam and fix the problems. Now I saw that my Escort not only has no sound again, but also there were no other tyres available. So I tried the replace Tyres button, but it didn't work. By draging the Tyres to the left, the cursor changed and I couldn't drop the tyres on the left side of the windows. Is it a bug or a feature? Is there a work around? I have googled the problem but found no solution.