Following the provided information, I was unable to replicate any errors when exporting the grid's content to a pdf file. That is why I have prepared a sample project for your reference. Could you please give it a try and see how it works on your end?
I have followed the following help article for building the project: https://docs.telerik.com/devtools/winforms/controls/gridview/exporting-data/export-to-pdf
I hope this information helps. If you need any further assistance please don't hesitate to contact me.
Dess | Tech Support Engineer, Sr.
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