I was aware of the danger and installed "macOS catalina", but there were many problems...
The biggest problem, in particular, was the extremely slow access to the web.Simple sites often took about a minute.
I suspected a lot about DNS, but it was a mystery because I was able to connect without any problems other than HTTP, but I found out the cause.
https://esupport.trendmicro.com/support/vb/solution/ja-jp/1123979.aspx
It was a virus buster issue.
The biggest problem, in particular, was the extremely slow access to the web.Simple sites often took about a minute.
I suspected a lot about DNS, but it was a mystery because I was able to connect without any problems other than HTTP, but I found out the cause.
https://esupport.trendmicro.com/support/vb/solution/ja-jp/1123979.aspx
It was a virus buster issue.
