Guild Wars 2

For the last 3 days I have been unable to continue my personal story.

At the beginning of the forewarned is forearmed personal story quest there is a graphical glitch of 4 blocks blocking the entrance to the sewers.
As shown is this picture: https://drive.google.com/file/d/0B_OEKsZ2piusRXNnRWxnSUFlQms/view?usp=sharing

It is impossible for me to start the personal story quest.

What can be done?

Have you tried entering the sewer from the other side?