One alternative is to modify /usr/bin/winetricks, which is a shell script, to include the updated sha256sum. You should do this only if you are sure that the file in your cache has been properly downloaded.
In my case, the error is:
sha256sum mismatch! Rename /home/coderazzi/.cache/winetricks/PowerPointViewer/PowerPointViewer.exe and try again.
I can check the sha256 sum of this file:
And the result is: e17cb384eeac4caf08a4f5d4bceb9697fff83fa942d2a3d9ad0294a9b1774390
grep PowerPointViewer.exe /usr/bin/winetricks
Shows a few lines with content:
... /PowerPointViewer.exe" 249473568eba7a1e4f95498acba594e0f42e6581add4dead70c1dfb908a09423
It can be updated now by replacing the original sum with the new one, just by doing:
sudo sed -i -e s/249473568eba7a1e4f95498acba594e0f42e6581add4dead70c1dfb908a09423/e17cb384eeac4caf08a4f5d4bceb9697fff83fa942d2a3d9ad0294a9b1774390/g /usr/bin/winetricks
Executing now winetricks would avoid the original error.