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IBExpert + Firebird 2.0

When entering any data into the fields, it gives the following error. The tables were created using the script:

CREATE TABLE Klient (
Kod_klienta integer NOT NULL PRIMARY KEY,
Familia varchar(25),
Imya varchar(25),
Otchestvo varchar(25),
Pasportnie_dannie integer,
INN integer,
SNILS integer
);

CREATE TABLE Credit (
Kod_kredita integer NOT NULL PRIMARY KEY,
Kod_klienta integer NOT NULL,
Nazvanie_kredita varchar(60),
Obshaya_summa_viplat decimal,
Summa_zaima decimal,
Procentnaya_stavka float,
Data_pervoi_viplati date,
Data_poslednei_viplati date,
FOREIGN KEY (Kod_klienta) REFERENCES Klient(Kod_klienta)
);

CREATE TABLE Viplata (
Nomer_viplati integer NOT NULL PRIMARY KEY,
Kod_kredita integer NOT NULL,
Data_viplati TIMESTAMP,
Summa_vipalti DECIMAL(10, 2),
FOREIGN KEY (Kod_kredita) REFERENCES Credit(Kod_kredita)
);

CREATE TABLE Kollektorskoe_agentstvo (
Kod_agentstva integer NOT NULL PRIMARY KEY,
Nazvanie_agentstva varchar(100),
YUridicheskoe_lico varchar(100),
Fizicheskoe_lico varchar(52),
Adres varchar(100)
);

CREATE TABLE Organizaciya (
Kod_organizacii integer NOT NULL PRIMARY KEY,
Familiya varchar(25),
Imya varchar(25),
Otchestvo varchar(25),
Nazvanie_organizacii varchar(52),
KPP integer,
OGRN integer,
INN integer
);

CREATE TABLE Trudovaya_deyatelnost_klienta (
Kod_klienta integer NOT NULL,
Kod_organizacii integer NOT NULL,
Zarabotnaya_plata integer,
Nazvanie_dolzhnosti varchar(100),
Data_nachala_raboty date,
Data_okonchaniya_raboty date,
PRIMARY KEY (Kod_klienta, Kod_organizacii),
FOREIGN KEY (Kod_klienta) REFERENCES Klient(Kod_klienta),
FOREIGN KEY (Kod_organizacii) REFERENCES Organizaciya(Kod_organizacii)
);

CREATE TABLE Krediti_peredannie (
Kod_kredita integer NOT NULL,
Kod_agentstva integer NOT NULL,
Data_peredachi_dokumentov timestamp,
PRIMARY KEY (Kod_kredita, Kod_agentstva),
FOREIGN KEY (Kod_kredita) REFERENCES Credit(Kod_kredita),
FOREIGN KEY (Kod_agentstva) REFERENCES Kollektorskoe_agentstvo(Kod_agentstva)
);

I tried to completely reinstall IBExpert and Firebird 2.0, it did not help. Newbie, I don’t understand anything