I have found a repeatable bug with buffer~ in Windows.

When loading audio into a buffer~ object where the audio is stored on a network drive, using a UNC path name ( \\sap123456\Share\Audio\file.wav ) the buffer~ returns a "cannot open parser for this file" error. If the network share is mapped to a drive letter and the drive letter path name is used ( S:\Audio\file.wav ) the buffer~ properly loads the file.

sfplay~ will load files from either path format.