App Store doesn't install keynote anymore after reinstallation of high Sierra

After reinstalling high Sierra the App Store doesn't allow me to install keynote or numbers. Pages worked just fine and so do other apps as well.

I get the error message:

" We could not complete your purchase. The product distribution file could not be verified. It might be damaged or was not signed."

I have tried the following already with no success:

1. new password to apple account

2. sign in and out of account

3. re authorize Mac with account in itunes

4. delete cache files (some of them and all of them)

Any idea what I can do? Some downloads simply don't work while others do. e.g. Mojave does have the same problem when trying to install from App Store.

Any help is appreciated.