The a0000191.dll error is associated with Microsoft MPEG-4 V1/2/3 VKI Codec. Typically, codec files are used to assist the end user in downloads of audio or video files. An a0000191.dll error message could mean a couple of different things.
Codec files have a reputation for silently carrying malware such as Trojans. It’s unknown if the a0000191.dll file contains a security threat to your computer or if there is an error with the file being misplaced, corrupted, damaged, or deleted.
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