We have several clients that are experiencing errors when accessing XML files out of their browser cache. The error disappears when Symantec's EndPoint software is uninstalled. We've been able to reproduce this problem by using the following steps:
- Clear IE cache
- Access the XML file using HttpWebRequest/HttpWebResponse objects in a C# program
- Access the XML file again with the same class objects only specifying the HttpRequestCacheLevel of "CacheIfAvailable". In that case, the XML file that is read from cache is missing the second 4K chunk. In other words, the first 4K is there and the 3rd 4K is there, but the 2nd is not to be found.
- Subsequent access to the same file is often successful, as if there were some sort of sandboxing that is providing an incomplete result on the second attempt.
When we remove the Symantec software from the Client PC, this issue goes away. I have writtten a test program in C# that reproduces this behavior and have attached it to this post.
-Brian Vandewettering