Edit not being saved ?

I'm a new user.

In the File management section of I have an .htm file that I uploaded.

If I hover over the file then my options include Edit or Modify with advanced editor.

I can check the box to select the file I want to edit.

I have tried both Edit and Modify and I have tried to Apply my edit and Save my edit but the date of the last change of the the .htm file remains unchanged and the file remains unchanged when I view it.

If I use Edit and click Apply I the the message "ERROR: XML response seems not valid." That is the only time I get an error message.

Please let me know what I am doing wrong. Thank you and sincerely, Peter

What browser are you using? What is the name of the file? Do you have the same problem with every file or only that one?

I am using Firefox 43.0.1
The file is bahamasdna.htm

Thank you for suggesting I edit other files. I was able to make a change on a file named bahydna.htm and a change on a file named bahmtdna.htm

I wonder what difference could be? bahamasdna.htm is 2 Mb. bahydna.htm and bahmtdna.htm are about 1 Mb each.

The file is too big, you won't be able to edit it in the control panel. You can however make the changes on your PC and then upload it (via FTP or the control panel).