"The input couldn't be recognized as a valid Excel document."

I realize this is an older post, but relevant nonetheless. I got the error of input not recognized as valid Excel document, and was able thanks to your instructions to save the file without changes and open the file in Power BI. 

The challenge I have is that I have a server folder full of these reports that I would like to transform and combine within Power BI based on folder location, without having to open and save each individual file. Do you know of a way within Power BI to resolve the XML issue, or perhaps something I can do with powershell to import the "restored" files?

Some background: the Excel files I'm trying to import are created and stored through an SAP batch job. Here's some information I copied from the Tracer:

04T15:20:36.0872649Z","Action":"ExcelReaderOpenXml/ExceptionHandler","HostProcessId":"14184","PartitionKey":"Section1/EXLIST_500_APAC_20200803030134/Source","Exception":"Exception:\r\nExceptionType: System.InvalidOperationException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089\r\nMessage: Specified part does not exist in the package.\r\nStackTrace:\n   at System.IO.Packaging.Package.GetPart(Uri partUri)\r\n   at Microsoft.Mashup.Engine1.Library.Excel.ExcelReaderOpenXml.RelationshipHidingPackage.GetPartCore(Uri partUri)\r\n   at System.IO.Packaging.Package.GetPartHelper(Uri partUri)\r\n   at System.IO.Packaging.Package.GetPart(Uri partUri)\r\n   at DocumentFormat.OpenXml.Packaging.OpenXmlPart.Load(OpenXmlPackage openXmlPackage, OpenXmlPart parent, Uri uriTarget, String id, Dictionary`2 loadedParts)\r\n   at DocumentFormat.OpenXml.Packaging.OpenXmlPartContainer.LoadReferencedPartsAndRelationships(OpenXmlPackage openXmlPackage, OpenXmlPart sourcePart, PackageRelationshipCollection relationshipCollection, Dictionary`2 loadedParts)\r\n   at DocumentFormat.OpenXml.Packaging.OpenXmlPartContainer.LoadReferencedPartsAndRelationships(OpenXmlPackage openXmlPackage, OpenXmlPart sourcePart, PackageRelationshipCollection relationshipCollection, Dictionary`2 loadedParts)\r\n   at DocumentFormat.OpenXml.Packaging.OpenXmlPartContainer.LoadReferencedPartsAndRelationships(OpenXmlPackage openXmlPackage, OpenXmlPart sourcePart, PackageRelationshipCollection relationshipCollection, Dictionary`2 loadedParts)\r\n   at DocumentFormat.OpenXml.Packaging.OpenXmlPackage.Load()\r\n   at DocumentFormat.OpenXml.Packaging.SpreadsheetDocument.Open(Package package, OpenSettings openSettings)\r\n   at Microsoft.Mashup.Engine1.Library.Excel.ExcelReaderOpenXml.ReadTablesUnguarded()\r\n   at Microsoft.Mashup.Engine1.Library.Excel.ExcelReaderOpenXml.ReadTables()\r\n\r\n\r

Thanks in advance for any tips/advice!