I have this same problem. Read to the bottom for a possible solution (if you have access to another computer.)
I have two computers, one for me and one for my daughter. On my computer, the file installed just fine. I got through the update and am able to play. The version of the install file is 1.180 and I got it from GamersHell.com.
On my daughter's computer, however, the installation file runs but then after a few minutes of "Please Wait" it comes up with "Client file is damaged. Please reinstall client."
I have tried removing all old SRO files before installing and I have even reinstalled the previous version (without the updates of course) and then tried the new install. In both cases, the same message appears. I tried rerunning with different compatibility settings and even went through the registry removing all reverenses to SRO (not recommended unless you know what you are doing.) In all cases, the error returned.
FOR WHAT IT IS WORTH:
I have read that the hardware requirements for the new Silkroad release might be different than they were before. This could explain the problem as my computer is somewhat newer than my daughter's.
MY SOLUTION:
This worked for me because I have two different computers. If you can get a friend with a working version of 1.180, perhaps it will work for you too.
1. I backed up the folder C:\Program Files\Silkroad\Setting
You might want to keep these as they tell the program what your computer uses for graphics and screen resolution, etc. Also, you would not want all those people you blocked to be able to talk to you again, now would you

.
2. I reinstalled an older version of SRO. This was just to get the registry settings back and to get the shortcuts on the menus and such, as I had deleted them all trying other things to fix this problem. You can skip this step if they are still there or you want to rebuild them manually (assuming you know what to do).
3. From my other computer, I copied the files from C:\Program Files\Silkroad\ to the problem computer's C:\Program Files\Silkroad. Then I copied the Setting folder I backed up in Step 1 to C:\Program Files\Silkroad\Setting. Note, both of these steps should overwrite all the files in the folders.
And voila ... daughter can play SRO with her dad again (if she ever gets off Furcadia that is

).
*Good Luck*