dll - Installation problem QGIS

I do not manage to install QGIS on my windows 10 machine using the osgeo4w installer.

During the installation I get this message:

At the end of the installation I get this message:

And when I subsequently try to run QGIS, I receive this message:

Similar issue can be found in various fora, but none of them provides a conluding answer or did help me to solve the problem.

Any propositions?

Answer

I managed finally to install QGIS as explained above. However, I am not able to backtrace the solution.

What I did, however, where (at least) the following steps:

1. Remove the entire OSGeo4w directory


2. Install QGIS with the standalonw installer (This worked)(https://qgis.org/en/site/forusers/download.html)


3. Uninstall QGIS again


4. Install QGIS with the OSGeo4w installer having the firewall/anti-virus disabled (This worked)


5. Uninstall QGIS and install it again having the firewall/anti-virus enables (This worked)

There might be other minor changes that have enabled the proper installation. However, I do not remember them or might not even be aware of them.

As pointed out by @AndreasMüller, the reason might be simply that the package had been fixed in the meantime.