Problem and any relevant assumptions:
1. User can obviously access the web interface and can successfully authenticate with provided credentials.

2. We can assume the Citrix client (whatever version) is installed correctly

3. User is prompted with the following error while attempting to launch a published application "ICA file not found" followed by the application failing to launch/start.

Possible Cause:
time to check the temporary internet files cache on the local workstaion. There is a good chance the cache is either way to large (like years of IE cookies and other junk) or the drive has been consumed entirely by some other process or application. This error is essentially the result of application latency or delay when attempting to save the .ica file locally and the local os (browser) is unable to access the file locally.

One of perhaps many solutions:
Time to dump your browser cache:

1. Open Internet Explorer and navigate to Tools > Internet Options....

   • 

2. On the General tab, click Delete Files....

   • 

3. If you happen to be using IE8 or IE7 you do have an option of deleting browsing history on exit. Option is available under Browsing history in the General tab.

4. If you are on an IE version prior to IE7,  you may want to click Settings and decrease the ammount of disk space used by your internet cache.

5. Click on Apply then OK and, close IE and fire up your citrix website and give it one more shot.

If that fails:

1. Open Internet Explorer again, and navigate to Tools > Internet Options.

2. On the Advanced tab, scroll to the Security section, and ensure that the checkbox for Do Not Save Encrypted Pages to Disk is deselected (is not selected).

   • 

3. Click OK and restart the browser.

If that fails:

1. Find the admin who id deploying bunk Active directory policy to your desktop. (chances are you wont be able to locate these people, or they have decided to forgoe any change control process).