Error when only 1 data in array

[rizkikurniaa]

hi, i got this error when data in array only 1 data but when its more than just 1 its running well. How to handle this?
FATAL EXCEPTION: main
Process: com.iss, PID: 2608
java.lang.UnsupportedOperationException
at java.util.AbstractList.remove(AbstractList.java:638)
at java.util.AbstractList$SimpleListIterator.remove(AbstractList.java:75)
at java.util.AbstractList.removeRange(AbstractList.java:658)
at java.util.AbstractList.clear(AbstractList.java:466)
at android.widget.ArrayAdapter.clear(ArrayAdapter.java:273)
at com.omarshehe.forminputkotlin.adapter.AutoCompleteAdapter$nameFilter$1.publishResults(AutoCompleteAdapter.kt:66)
at android.widget.Filter$ResultsHandler.handleMessage(Filter.java:282)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)