Unable to create new field if (other) fieldtype is missing

[intoeetive]

This happens if fieldtype was not correctly uninstalled (e.g. there's still field assigned to this type in exp_channel_fields) but the addon files were deleted

If you try to create new field, you get the error

Error: Unable to load requested fieldtype file: ft.cypress_addon.php.
Confirm the fieldtype file is located in the /system/user/addons/ directory

Same issue exists if you go to publish new entry - though in that case it might be expected, but only if the field is assigned to given channel

This should be silently ignored instead