Rather than downloading a random file from the internet, let your game launcher provide a fresh, official copy.
Restore the file if your AV flagged it as a false positive.
If you have multiple games installed (e.g., both Warframe and Elden Ring ), they likely both use Oodle. Go to the folder of a game that working. Search for oo2core_9_win64.dll .
In some cases, users manually copy a known "good" version from one game folder to another.