Server VDAs from a machine catalog using the MCS I/O feature blue screen with message: SYSTEM_THREAD_EXCEPTION_NOT_HANDLED (CtxMcsWbc.sys) 

After creating Machine Catalogs with the MCS I/O feature, log on the VDA and check that an extra uninitialized disk exists on Disk management.

Do not attempt to format it or initialize it.



If there is no extra cache drive on the VDAs, the catalog needs to be recreated.

 

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Problem Cause

The extra drive for the write back cache was not created, and when the temporary memory has reached its threshold, the cached data cannot be written to a hard disk, thus the machine bluescreens.