Problem with Survey Module in Chamilo 1.11 [Solved]

[moigaston2]

Hello everyone,
I am currently trying to subscribe approximately 1,500 students to a survey in Chamilo. To do this, I use the interface with two windows: one on the left listing all course participants, and one on the right for survey subscribers. However, after I select the students, move them to the right window, and click to save, they are immediately and automatically moved back to the left window. Has anyone encountered this issue before?
How can I resolve this problem and successfully subscribe all these students to the survey?
Thank you for your help!

[moigaston2]

I found a solution to work around the problem indirectly: I sent the direct link to the survey (provided in the survey settings) to all students by email, so they can open it directly in their browser.