At first I missed the error, now I am sure that a total of 3 counters permanently show "zero". The "summary box" on the overview page SlimStat works perfectly only on the dashboard is the error observed.
This applies to the counters: "Average page views.", "Unique IPs" and "Page Views XX / XXXX". At first I thought that the "german umlauts" (a typical encoding proplem) are responsible for the error, but deleting the language files did not change the error. Next, I have installed the files manually via FTP, with no success. Then I deleted the database and recreated it from scratch by the program.
To be honest, I have no idea how I can fix the problem.
Thanks in advance for your help.