Hi,

this issue is related to other issues regarding the export of quiz statistics to Excel (xlsx) and OpenOffice (ods) (ie. MDL-62833) with worksheets for the individual questions.

In this case the error happens when a quiz has more than one question with a long similar name, different from each others only for the last few chars.

ie.

• A long question name that differs only for last chars 00
• A long question name that differs only for last chars 01
• A long question name that differs only for last chars 02

Since Excel requires sheetname with max 32 chars, the long question names are truncated, resulting with potentially same duplicated names (is. A long question name that diff).

Exception - The sheet's name (""A long question name that diff") is invalid. It did not respect these rules: - It should be unique

Debug:
Error code: generalexceptionmessage

• line 137 of /lib/spout/src/Spout/Writer/Common/Sheet.php: Box\\Spout\\Writer\\Exception
  InvalidSheetNameException thrown
• line 87 of /lib/spout/src/Spout/Writer/Common/Sheet.php: call to Box\\Spout\\Writer\\Common
  Sheet->throwIfNameIsInvalid()
• line 89 of /lib/classes/dataformat/spout_base.php: call to Box\\Spout\\Writer\\Common
  Sheet->setName()
• line 1782 of /lib/tablelib.php: call to core\\dataformat
  spout_base->start_sheet()
• line 423 of /mod/quiz/report/statistics/report.php: call to table_dataformat_export_format->output_headers()
• line 902 of /mod/quiz/report/statistics/report.php: call to quiz_statistics_report->output_individual_question_response_analysis()
• line 197 of /mod/quiz/report/statistics/report.php: call to quiz_statistics_report->output_all_question_response_analysis()
• line 97 of /mod/quiz/report.php: call to quiz_statistics_report->display()

Thanks,

Giorgio