I need help with a virus chest problem

I have been using Avast anti-virus for about a year now and ive had no problem until now.Every time that i scan my computer an it finds infected files i just send them to the virus chest.But at the end when it shows me the results it says that an error occurred when it was sending it to the virus chest.And i keep on scanning it and it just says the same thing.
What can i do? ???

What is the malware name, the infected file name, where was it found e.g. (malware name, C:\windows\system32\infected-file-name.xxx) ?
Check the avast! Log Viewer (right click the avast ‘a’ icon), Warning section, this contains information on all avast detections. C:\Program Files\Alwil Software\Avast4\ashLogV.exe

  • Or check the source file using notepad C:\Program Files\Alwil Software\Avast4\DATA\log\Warning.log and copy and paste the entry.

What is the file size ?