C# - APP: Exception: The operation was canceled.

[strakamichal]

Hi all,
i need help with one exception. I know only .Message of this exception and i know which part of code throws it.

.Message: "The operation was canceled."
 

               try
                  {
                      FileIOPermission perm = new FileIOPermission(FileIOPermissionAccess.Write, file_name);
                      perm.Assert();
                      if (!additive && File.Exists(file_name)) File.Delete(file_name);
                      using(FileStream fs = new FileStream(file_name, FileMode.OpenOrCreate, FileAccess.ReadWrite))
                      {
                          using(StreamWriter writer = new StreamWriter(fs))
                          {
                              writer.BaseStream.Seek(0, SeekOrigin.End); 
                              writer.Write(content); 
                              writer.Flush(); 
                              writer.Close();
 
                              result = true;
                          }
                          fs.Close();
                      }
                      CodeAccessPermission.RevertAssert();
                  }
                  catch (System.Exception err)
                  {
                      System.Diagnostics.Debug.WriteLine(err.Message);
                      throw(err);
                  }
 

FYI: This Windows application runs for many years, but once this error was occured and stored in log. Can somebody help me? Is anythere List of exception messages, where I can find what does the exception mean?

Thanks,
Michal

[kenobewan]

So this error has only happened once. Could it be a file permissions error?

[strakamichal]

Yes, it happened once. But I'am not sure with permissions error. I try to write to readonly file or disconnect virual hardisk during writing, but error message is different.