error on feuser edit: is not integer - typo3

Question

I extend feuser with custom fields. All work good. If I type integer value it was save good. But if I type string value I get error - 1332933658: "" is no integer. You can see this on the follow screenshots.
enter image description here
ext_tables.php
#
# Table structure for table 'fe_users'
#
CREATE TABLE fe_users (
aboutmyself varchar(255) DEFAULT '' NOT NULL,
aboutmypartner varchar(255) DEFAULT '' NOT NULL,
tx_extbase_type varchar(255) DEFAULT '0' NOT NULL,
);
Model:
<?php
namespace Fhk\Feusersplus\Domain\Model;
/***************************************************************
*
* Copyright notice
*
* (c) 2017
*
* All rights reserved
*
* This script is part of the TYPO3 project. The TYPO3 project is
* free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* The GNU General Public License can be found at
* http://www.gnu.org/copyleft/gpl.html.
*
* This script is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* This copyright notice MUST APPEAR in all copies of the script!
***************************************************************/
/**
* User
*/
class User extends \In2code\Femanager\Domain\Model\User
{
/**
* aboutmyself
*
* #var int
*/
protected $aboutmyself = '';
/**
* aboutmypartner
*
* #var int
*/
protected $aboutmypartner = '';
/**
* Returns the aboutmyself
*
* #return int $aboutmyself
*/
public function getAboutmyself()
{
return (string)$this->aboutmyself;
}
/**
* Returns the aboutmypartner
*
* #return int $aboutmypartner
*/
public function getAboutmypartner()
{
return (string)$this->aboutmypartner;
}
/**
* Sets the aboutmyself
*
* #return void
*/
public function setAboutmyself($aboutmyself)
{
$this->aboutmyself = (string)$aboutmyself;
}
/**
* Sets the aboutmypartner
*
* #return void
*/
public function setAboutmypartner($aboutmypartner)
{
$this->aboutmypartner = (string)$aboutmypartner;
}
/**
* __construct
*/
public function __construct()
{
//Do not remove the next line: It would break the functionality
$this->initStorageObjects();
}
/**
* Initializes all ObjectStorage properties
* Do not modify this method!
* It will be rewritten on each save in the extension builder
* You may modify the constructor of this class instead
*
* #return void
*/
protected function initStorageObjects()
{
}
}

Answer 1

The type hint for your fields aboutmyself and aboutmypartner is defined as
#var int
but you store a VARCHAR. Try changing the hint to
#var string
and clear all caches (also, emptying the typo3temp folder can't hurt).