Error when compiling to WebGL: Destination directory not found

When I try to compile my project to WebGL in Development mode on Windows 8.1, I receive the following errors (the first one is truncated because it's really long; I can post it upon request).

DirectoryNotFoundException: Destination directory not found: Temp/StagingArea/Data/Resources System.IO.File.Copy (System.String sourceFileName, System.String destFileName, Boolean overwrite)...

Error building Player: DirectoryNotFoundException: Destination directory not found: Temp/StagingArea/Data/Resources

There's no output; the directory I'm attempting to build my project in is empty. A forum post somewhere suggested I run Unity in Administrator mode, but if that had worked I wouldn't be posting here for help.