Teampass 2.1.27.4 - Can not decrypt a created crypted Backup

[userrst]

Steps to reproduce

1. Open Teampass in Admin Mode
2. Go to Backup menu
3. Put in the backup name without .sql
4. Push the Start Button

Expected behaviour

Decrypt a created crypted Backup file like bck_teampass-1496260837.sql

Actual behaviour

I can not decrypt a created crypted backup

Server configuration

Operating system: CentOS Linux release 7.3.1611

Web server: httpd 2.4.6

Database: mariadb 5.5.52

PHP version: 5.5.38

Teampass version: 2.1.27.4

Client configuration

Browser: Newest Firefox

Operating system: Windows 10 64Bit

Logs

Web server error log

No error Log

Firebug log (How to?)

ReferenceError: reference to undefined property 0
jquery.js (line 3990, col 1)

ReferenceError: reference to undefined property "_defaultEngine"
content...chUI.js (line 76, col 5)

[nilsteampassnet]

I have improved this.
It now uses defuse encryption to speed up the decrypt and encrypt process.
Reopen if needed.