When I click on any "Update" link in my DNN 4.0.2 portal I get the following js error 'WebForm_PostBackOptions' is undefined. 

 I am not running compression.

It was working two weeks ago, but since then receive error.  I was able to update from another computer until a few days ago.

I am not sure but I think it might be linked with a recent MS security update (not sure which one though).  Cannot find any information on this problem other then dealing with Compression.

Please help.

Bryan

Hi guys

After reading all your comments, I wanted to give you my solution to this problem, after a long experiments, this is how it was solved out for me.

The cause: The new dnn compression, which compresses the resource.axd file, and makes it no longer usefull.

1. Go to Host settings. Disable compression.

2. Clear the cache files. and restart app.

3. clear you temporary internet files on the browser.

4. close the browser!

5. Restart the website - from IIS. This will clean for sure all the cache files, and stop the compression mechanism.

GL

Shai Eden