Because acqdll talks to the dongle, outdated drivers are the #1 cause of “cannot initialize acquisition module.”
If the file is permanently deleted, the most reliable fix is to perform a clean uninstall and reinstall of ArtCAM Pro 8.1. User Account Control (UAC)
Ensure you are running ArtCAM on a supported OS; ArtCAM Pro 8.1 is legacy software and may require compatibility modes for modern Windows versions. Key Features of ArtCAM Pro 8.1
Sometimes manually downloading and placing the missing DLL into the System32 folder or the application directory can fix specific "not found" errors.