I moved a site to another server, it worked fine for a a while, but then crashed. I figured out that System.Web.Extensions.dll was missing, so I copied it again. After a while it was missing again. Using Process Monitor I figured out that IIS (w3wp.exe) deletes the file soon after I copy it to the bin folder. (CreateFile with "Read Attributes, Delete" access.)
造成这种行为的原因何在?