Failed to convert WAV for AIF

[Gatekeeper101]

See errors below - any idea whats wrong as it worked before ?
Error Cannot Create Wave Decoder (Unknown ACM ID: 65026 (ACM decoder not installed))? [clWaveDecoder_Wave::PrepareToDecodeAudio]

Error converting to Aiff, 'E:\Temp\Track 02.wav' to 'C:\Temp\Track 02.aif'
Error Cannot Create Wave Decoder (Unknown ACM ID: 65026 (ACM decoder not installed))? [clWaveDecoder_Wave::PrepareToDecodeAudio]

Error converting to Aiff, 'E:\Temp\Track 03.wav' to 'C:\Temp\Track 03.aif'
Error Cannot Create Wave Decoder (Unknown ACM ID: 65026 (ACM decoder not installed))? [clWaveDecoder_Wave::PrepareToDecodeAudio]

[Spoon]

Wave is a container, there are many different sub formats, such as voice recorders which have their own unique compression. Such products would come with a driver disk which would install an ACM driver which would allow any program on Window to read that special format.