After updating Clickhouse as described in https://clickhouse.yandex/docs/en/operations/update/ from version 19.3.5 to 19.17.4.11, clickhouse-server service refused to start. I have Ubuntu 18.04.1 LTS.

How to reproduce

• Clickhouse version - 19.3.5, user settings stored in /etc/clickhouse-server/users.xml. Password for user "default" is stored in <password_sha256_hex></password_sha256_hex> block
• Updating to the newest version (19.17.4.11 in my case)
• During the update system asks for password for default user; I entered it
• Choose to keep previously created config files
• Restarting clickhouse-server daemon -> service doesn't start

Expected behavior
Service "clickhouse-server" restarts without errors after update.

Error message and/or stacktrace
When trying to start clickhouse-server:
Poco::Exception. Code: 1000, e.code() = 0, e.displayText() = Cannot create file: Cannot create pid file. (version 19.17.5.18 (official build)

In /var/log/clickhouse-server/clickhouse-server.err.log:
<Error> Application: DB::Exception: More than one field of 'password', 'password_sha256_hex', 'password_double_sha1_hex' is used to specify password for user default. Must be only one of them.

How I solved the problem
Deleted "users.d" folder with conflicting settings that was created after an update.