Error creating file!

[RealTechSide]

UnityException: Creating asset at path C:/ArpaRec/PortalRebornVelocityBeta/Assets/PortalRebornGame/Content/prtlmats/METAL/BLACK_FLOOR_METAL_001D_CHEAP.mat failed. BSPImporter.BSPLoader.LoadMaterial (System.String textureName) (at Library/PackageCache/com.wfowler1.unity3d-bsp-importer@800c5f21c6/Runtime/Util/BSPLoader.cs:424) BSPImporter.BSPLoader.CreateFaceMesh (LibBSP.Face face, System.String textureName) (at Library/PackageCache/com.wfowler1.unity3d-bsp-importer@800c5f21c6/Runtime/Util/BSPLoader.cs:682) BSPImporter.BSPLoader.BuildMesh (BSPImporter.BSPLoader+EntityInstance instance) (at Library/PackageCache/com.wfowler1.unity3d-bsp-importer@800c5f21c6/Runtime/Util/BSPLoader.cs:536) BSPImporter.BSPLoader.LoadBSP (LibBSP.BSP bsp) (at Library/PackageCache/com.wfowler1.unity3d-bsp-importer@800c5f21c6/Runtime/Util/BSPLoader.cs:226) BSPImporter.BSPLoader.LoadBSP () (at Library/PackageCache/com.wfowler1.unity3d-bsp-importer@800c5f21c6/Runtime/Util/BSPLoader.cs:181) UnityEngine.Debug:LogException(Exception) BSPImporter.BSPLoader:LoadBSP() (at Library/PackageCache/com.wfowler1.unity3d-bsp-importer@800c5f21c6/Runtime/Util/BSPLoader.cs:189) BSPImporterWindow:DrawImportButton() (at Library/PackageCache/com.wfowler1.unity3d-bsp-importer@800c5f21c6/Editor/BSPImporterWindow.cs:141) BSPImporterWindow:OnGUI() (at Library/PackageCache/com.wfowler1.unity3d-bsp-importer@800c5f21c6/Editor/BSPImporterWindow.cs:40) UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)