The icons are restored and look clear![/quote]
After the above restore, the same error occured at every activation.
I found the following situation;
1. Icons on dock are displayed normally in 32 bit size!
2. In more than 32 bit, some icons are not displayed normally., corrupted.
I never experienced this error in the previous macOS sierra, it arose in High sierra!
Plaese check and let us know the solution.