Hi Fabian, forgot to mention that I downgraded the package to version 1.07.4-1 before the experiments with the harfbuzz packages. Therefore, I had to upgrade fonts-liberation also.
Now, on a second system I did only this up-, down-, and upgrading of fonts-liberation package (1.07.4-1 -> 2.00.1-2 -> 1.07.4-1 -> 2.00.1-2). On that system I don't see the problem with the German umlauts. Regards, jvp.
