When I try to export a ReportBook to TIFF as explained in Exporting a report to a multi-document format, I receive an exception related to the file '.../report/image.tif' that cannot be created.

When I create the folder '.../report', there is another exception message:

'The process cannot access the file '...\report\image.tif' because it is being used by another process.'

The above error was thrown the second time the ReportProcessor tried to access the 'CreateStream' method from the code snippet in the above article. The 'image.tif' file is created and contains only the first report from the ReportBook.

With version 15.0.21.112 the last exception is not thrown and the 'image.tif' file contains all reports from the ReportBook.