This is:

- [ ] a bug report

What is the expected behavior?

XLS file exports neatly.

What is the current behavior?

Export crashes halfway.

What are the steps to reproduce?

Export the file.
$writer = new \PhpOffice\PhpSpreadsheet\Writer\Xlsx($spreadsheet);
on
Apache/2.4.41 (Win64) OpenSSL/1.1.1c PHP/7.3.12

First time I encounter this issue. Could it be memory-related?

Fatal error: Uncaught PhpOffice\PhpSpreadsheet\Calculation\Exception: Dialogs!AA2 -> internal error in C:\xampp\htdocs\ModernMT\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Cell\Cell.php:270 Stack trace: #0 C:\xampp\htdocs\ModernMT\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Writer\Xlsx\Worksheet.php(1113): PhpOffice\PhpSpreadsheet\Cell\Cell->getCalculatedValue() #1 C:\xampp\htdocs\ModernMT\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Writer\Xlsx\Worksheet.php(1183): PhpOffice\PhpSpreadsheet\Writer\Xlsx\Worksheet->writeCellFormula(Object(PhpOffice\PhpSpreadsheet\Shared\XMLWriter), '=IFERROR(__xlud...', Object(PhpOffice\PhpSpreadsheet\Cell\Cell)) #2 C:\xampp\htdocs\ModernMT\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Writer\Xlsx\Worksheet.php(1040): PhpOffice\PhpSpreadsheet\Writer\Xlsx\Worksheet->writeCell(Object(PhpOffice\PhpSpreadsheet\Shared\XMLWriter), Object(PhpOffice\PhpSpreadsheet\Worksheet\Worksheet), 'AA2', Array) #3 C:\xampp\htdocs\ModernMT\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsh in C:\xampp\htdocs\ModernMT\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Cell\Cell.php on line 270