Squirrel-Sql client fails to connect to MySQL 8 with "Unexpected Error occurred attempting to open an SQL connection"

I have been using Squirrel SQL to query MySQL 5.7 databases from my Windows 10 laptop. We are now starting to upgrade to MySQL 8, but when I try to connect to a MySQL 8 instance I'm getting the error, "Unexpected Error occurred attempting to open an SQL connection. class java.lang.NullPointerException: null". The stack trace is shown below. I found a similar question about this error that suggested increasing memory allocation, which I did but it didn't help. (Since the squirrel-sql.bat file didn't set -Xmx at all, I added it. Documentation shows that javaw default is 256m so I went up to -Xmx4096m but same error.)

BTW I'm using Java corretto-11.0.8.10.1.

Has anyone been successful using Squirrel-Sql with MySQL 8?

Here is the stack trace:

java.lang.NullPointerException
    at com.mysql.jdbc.ConnectionImpl.getServerCharset(ConnectionImpl.java:3005)
    at com.mysql.jdbc.MysqlIO.sendConnectionAttributes(MysqlIO.java:1916)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1845)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1215)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2255)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2286)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2085)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:795)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:400)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:327)
    at net.sourceforge.squirrel_sql.fw.sql.SQLDriverManager.getConnection(SQLDriverManager.java:147)
    at net.sourceforge.squirrel_sql.client.mainframe.action.OpenConnectionCommand.executeConnect(OpenConnectionCommand.java:136)
    at net.sourceforge.squirrel_sql.client.mainframe.action.OpenConnectionCommand.lambda$execute$0(OpenConnectionCommand.java:93)
    at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
    at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:834)

I downloaded mysql-connector-java-8.0.21.jar through Maven and copied it to my Squirrel-SQL lib directory and restarted Squirrel-Sql. Problem solved!