Hi

You need to go into PhpMyadmin and alter the database:

TEXT types can 64K of data, while LONGTEXT can hold 4GB of data, therefore this can cause a problem while entering such large number of cities.

I suggest to change the `value` type of the k2_extra_fields table from TEXT to LONGTEXT.

This is what worked for me.

Thread here:

getk2.org/community/New-to-K2-Ask-here-first/178535-drop-down-fields-in-K2-extra-fields-vanish#178597

Kind regards
Arthur