It's a part of Acrobat Professional. Try to Repair Acrobat Professional installation. If it doesn't help, reinstall.

>
>I am using MergePDf function, where I have a line:
>
>loAcroApp = CREATEOBJECT("AcroExch.App")
>
>for a long time.
>
>Suddenly, this morning I've got an error:
>OLE error code 0x80040154: class not registered.
>What class should I register? what is the name of DLL for this APP?
>Any advice will be very helpful
>
>TIA
>Jerry