Ive been running into this problem ever since I updated the module to 7.x-1.1 and also updated the pdf.js to the current version in git.

Fortunately, Ive managed to fix it for myself changing the line 62 from:

$file_url = file_create_url($variables['file']->uri);

to:

$file_url = file_create_url($variables['file']['uri']);

I hope this can help anyone with a similar problem.

Comments

You may need to use the latest file_entity module.
If I remember correctly, I change the code because of it.

@Jonathan I had the same problem. Thank you so much for your solution. Works great.
P.S. I am running this on a multi-site install.

Status:Active» Closed (fixed)

fixed.