Solution for "Padding is invalid and cannot be removed."

This error relates to encryption.

1. You don't have all the encryted string, so when decrypting, it's not valid

When using CryptoStream, you forgot to force it to encrypt the last bytes of the stream. It keeps bytes in an internal buffer until enough of them arrive to emit a block. You must force the last few bytes out. Try using this code :

using (var msEncrypt =newMemoryStream())
  using (var csEncrypt =newCryptoStream(msEncrypt, encryptor,CryptoStreamMode.Write))
    using (var swEncrypt =newStreamWriter(csEncrypt))
    {
      swEncrypt.Write(plainText);
      csEncrypt.FlushFinalBlock();
      encrypted = msEncrypt.ToArray();    }

https://stackoverflow.com/questions/10469819/padding-is-invalid-and-cannot-be-removed-exception-while-decrypting-string-using
https://www.red-gate.com/simple-talk/blogs/oh-no-my-paddings-invalid/

2. Remove the padding from the algorithm

aes.Padding=PaddingMode.None;

https://stackoverflow.com/questions/5080267/c-aes-error-padding-is-invalid-and-cannot-be-removed-same-key-and-everything/5080629#5080629

Localized versions of this error

الحشو غير صالح ولا يمكن إزالته.

Výplň je neplatná a nelze ji odebrat.

Udfyldningen er ugyldig og kan ikke fjernes.

Zeichenabstände sind ungültig und können nicht entfernt werden.

Η συμπλήρωση δεν είναι έγκυρη και δεν είναι δυνατό να αφαιρεθεί.

El relleno entre caracteres no es válido y no se puede quitar.

Täyttö on virheellinen, eikä sitä voi poistaa.

Le remplissage n'est pas valide et ne peut pas être supprimé.

הרווח אינו חוקי ואין אפשרות להסירו.

A kitöltés érvénytelen és nem távolítható el.

Il riempimento non è valido e non può essere rimosso.

パディングは無効なので、削除できません。

패딩이 잘못되었으며 제거할 수 없습니다.

Opvulling is ongeldig en kan niet worden verwijderd.

Utfylling er ugyldig og kan ikke fjernes.

Uzupełnienie jest nieprawidłowe i nie można go usunąć.

O preenchimento é inválido e não pode ser removido.

O preenchimento é inválido e não pode ser removido.

Заполнение неверно и не может быть удалено.

Utfyllnaden är ogiltig och går inte att ta bort.

Doldurma geçersiz ve kaldırılamaz.

填充无效，无法被移除。

填補無效，而且無法移除。

Disclaimer
Those solutions have been provided to you without any guarantee, they have been found on different help forums and brought to you here to ease your resolution process.