This information applies to versions 4 and older
NOTE: This does not apply to the reworked version of Analog Efex included in Nik Collection 5 and newer.
If you notice effects like this on your Apple computer with an Apple Silicon chip, please start the Nik Application with Rosetta.
Right-click the program icon, go to "Information" and enable the check-box "Open with Rosetta".
If this still does not help, disable the GPU processing option in Analog Efex's settings.