Answer: Please see followings:

The wiper wipes off ink stuck on the head nozzle surface. If the wiper gets dirty, the warning message “!REPLACE WIPER” or “!CLEANING WIPER” appears to prompt the cleaning (or replacement)
of the wiper. Please clean (or replace) the wiper. The wiper needs to be replaced roughly every six months. However, if the nozzle missing or ink dripping is not solved even after cleaning the wiper, replace it.

[Cleaning (replacement) procedure]

Execute [MAINTENANCE] -> [STATION] -> [MENT: WIPER EXCHG] or
　　　　[MENT: WIPER CLEANING].

* Either “WIPER EXCHG” or “WIPER CLEANING” is displayed depending on the
　firmware version of the main unit.
* The firmware is a program that controls the main unit.

For the cleaning tools and the detailed replacement procedure, see
“OPERATION MANUAL” -> “Chapter 4 Maintenance”-> “WIPER CLEANING”.

* The warning message continues to be displayed unless you execute the
　”WIPER EXCHG (WIPER CLEANING)” menu after replacing the wiper.
　This is because the internal wiping count is only reset when the
　”WIPER EXCHG (WIPER CLEANING)” menu is executed.