Bug 'Index and length must refer to a location within the string.'

We use version 4.0. From nop log file this is the error:
Log level
Error
Short message
Error while running the 'Import' import price and update manager creating task. Index and length must refer to a location within the string.
Parameter name: length
Full message
System.ArgumentOutOfRangeException: Index and length must refer to a location within the string.
Parameter name: length
   at System.String.Substring(Int32 startIndex, Int32 length)
   at FoxNetSoft.Plugin.Feed.ImportManager.Extentions.ImportTemplateExtentions.SaveReport(ImportTemplate importTemplate, IList`1 reportMessages, ReportLevel reportLevel)
   at FoxNetSoft.Plugin.Feed.ImportManager.Core.ImportManagerProcessingAbstract.ExecuteImportBase(ImportTemplate importTemplate, Boolean fake)
   at FoxNetSoft.Plugin.Feed.ImportManager.Core.ImportManagerProcessingCSV.ExecuteImport(ImportTemplate importTemplate, Boolean fake)
   at FoxNetSoft.Plugin.Feed.ImportManager.Core.ImportManagerThread.ImportImportTemplate(ImportTemplate importTemplate, Boolean fake)
   at FoxNetSoft.Plugin.Feed.ImportManager.Controllers.ImportManagerTaskController.RunTask(Int32 id, Boolean fake)

Thank you.

Version 1.03 - June 10, 2018

- fixed bug 'System.ArgumentOutOfRangeException: Index and length must refer to a location within the string.'. We can't replicate it.
+ added new feature 'plugin changes the flag "Published" or "Disable buy/wishlist buttons"'