Running into the 'Unable to open archive file' error when loading AssetBundle on WebGL build

As the title explains, I'm trying to set a variable using the AssetBundle.LoadFromFile() method and am encountering the error 'Unable to open archive file: filepath'. When I click on my filepath link in the Console, it downloads the file I expect and is seemingly just not setting my loadedAssetBundle variable properly.

I currently have prefabs labeled under the AssetBundle(s) I'm trying to save, but have also tried simple scenes (ie just a cube) and simpler prefabs as well. I get the same error every time and have been halted by this issue. I've posted some images of my code and the console error as well to help clarify how it's set up. Any help / advice is very much appreciated. Thanks!

 

FIX: I believe the issue was solved by first bringing in the file as a UnityWebRequest and then using DownloadHandlerAssetBundle.GetContent() to turn it into a usable AssetBundle. Here's the change that seems to have cleared up the issue.

 

I ran into this same problem and the search engine brought me here. It is true that AssetBundle.LoadFromFile is using file system and on WEBGL the way to find a resource is by URL scheme. So, the change from LoadFromFile to UnityWebRequest can make use of URL scheme and successfully find the file you want.