MPScanSkip error codes

From the MPScanSkip log file, does anyone know what these error codes are 

C:\ProgramData\Microsoft\Windows Defender\Support\MPScanSkip-xxxxxxxx-xxxxxx.log

OnDemandScan skipped or partial scan for [filepath]. Reason [Scan Error]. Error Code [80500021]

OnDemandScan skipped or partial scan for [pid:xx]. Reason [Scan Error]. Error Code [8050012b]

OnDemandScan skipped or partial scan for [process]. Reason [Scan Error]. Error Code [8050007b]