Please check the number of columns in the produced Excel file.
In case you are reaching the limit of 256 Excel columns in an XLS file, you can export in XLSX - Excel Limitation
s. Details about the required settings to have XLSX export are available in Missing DOCX, XLSX, PPTX, XPS export options.
Check also the type of fields displayed by the removed columns and if you use any formatting (TextBox.Format or Format text function) which may fail if the type of the fiedl cannot be formatted with the given format.
If you need further help, please open a support ticket and send us a demo report and test data reproducing the problem.
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