Hi @Baris ,
In the following post @anon89812132 gave a hint to solve your problem.
‘Update archive corrupted’
Also, in the forum there is another post written by @gan which suggest the same solution.
‘[Stable Update] 2020-08-28 - Kernels, Systemd, PAM, PAMBASE, KDE-git, Deepin, Pamac, Nvidia 450.66, LibreOffice 7.0 - #202 by vasmakk’
Regards,