can't save file to launch minecraft

Unable to save download. ast_es.lang
Name: ast_es.lang
URL: http://resources.download.minecraft.net/48/485585c4162664d3505c53324dbb7517a274d6da
Error details: Attempting to move successful download to C:/Users\Nick\AppData\Roaming\.minecraft\assets\objects\48/485585c4162664d3505c53324dbb7517a274d6da
The process cannot access the file because it is being used by another process
Filename on disk: 494a-e7c2-69d5-c036
Path: C:\Users\Nick\AppData\Local\Temp\494a-e7c2-69d5-c036
Exists: file