Getting errors trying to load asset bundle, help appreciated

I'll start with the errors themselves. The first is : Assertion failed on expression: 'm_UncompressedBlocksOffsets[blockInd] <= from + dstPos && m_UncompressedBlocksOffsets[blockInd] + uncompressedBlockSize >= from + dstPos' UnityEngine.AssetBundle:LoadFromFile(String)

Followed by : Failed to decompress data for the AssetBundle 'D:/Unity/projects/PQv0.10/Assets/AssetBundles/spritesbundle'. UnityEngine.AssetBundle:LoadFromFile(String)

I've always just used the resources folder for my projects but my current project has outgrown what that method can accommodate. So I'm trying to offload assets (in this case 5000 or so sprites)into an assetbundle and load them as needed at runtime. I figured I could just get a reference to the assetbundle and then call assetbundle.LoadAsset(assetname), substituting my old Resources.Load calls. Here's my attempt at making the assetbundle reference that keeps erroring:

 void loadSpritesBundle()
     {
         sprites = AssetBundle.LoadFromFile(Application.dataPath + "/AssetBundles/spritesbundle");
     }

For due diligence, here's also the code I used to create that assetbundle:

 public static void SaveSpecificAssets()
     {
         AssetBundleBuild build = new AssetBundleBuild();
         build.assetBundleName = "spritesBundle";
 
         string[] files = AssetDatabase.GetAllAssetPaths();
         List<string> validFiles = new List<string>();
         foreach (string file in files)
         {
             if (file.EndsWith(".png")) validFiles.Add(file);
         }
 
         build.assetNames = validFiles.ToArray();
 
 BuildPipeline.BuildAssetBundles("Assets/AssetBundles", new AssetBundleBuild[1] { build }, BuildAssetBundleOptions.None, BuildTarget.StandaloneWindows);
     }

The assetbundle builds without errors and appears in the directory where it should be. I have no indication that it's faulty other than the errors I get when trying to load it. If I'm missing any relevant information, please point it out and I'll try to provide it.