Cannot load tile

Hi,

All the tiles was ok. Today, I saw "Cannot load tile". It was working ok when the consultants set it up.

Questions:

1) How to find out which apps cannot load? From the Launchpad, there's no title on the apps that have problem loading.

2) I checked authorization, no changes on authorization since it has been set up.

3) Is there any error log file to find out what is the problem?

Hope to have some guidelines.

Thank you.

regards,

zl