I had just added the final touches to my course, saved, closed and then opened the course. When I tried to opened the course I got the following error message: The module could not be opened. Line 3911, pos 31, white space is not allowed at this location.

Now my course will not open for me to be able to edit or publish.

Can you please help???  

Hi, David,

perhaps some illegal (for XML) character has been inserted or copied from Word (presumably in Slide Name).

To fix that - please open module design file (located in module folder and named after the module - for example 1.xml or 2.xml) with any plain text editor (I mean Notepad or Notepad++ or some tool like that). Go to the line and position, that mentioned in error message (Ctrl-G option in Notepad). It seems that there is an extra unmasked quote somewhere in this line before position 31. Just remove it, to get a plain attribute name-value pairs in quotes (i.e. attribute="value"). You can also open the file with Internet Explorer to check it - IE also displays where invalid XML is located.