Gnucash issues

[INTECIPRO Salta]

To Gnucash development team:

I am writing this e-mail, to ask you for a solution to a problem I am
having with your software.
Today, as usual, I have been trying to work with Gnucash 2.4.11 and the
software did not open the books I have been working with. It says everytime
I try to open the books:  Cannot find backend.
This causes me many problems with my work because I cannot acces to firm's
customers data, and fulfilling my duties has been compromised.
Could I ask you to look in to this matter?
I look forward to hearing from you.
Yours sincerely

Rafael Bustamante