Spreadsheet hanging when open xlsx file

When I load example testpageok.xlsx into any of your demo pages it works.

But when I open tespage.xlsx it just freezes. This page only has two lines more identical to the lines above it.

Hi @Ferose,

We will need the actual file that causes the hang in order to reproduce it. Feel free to open an issue in the github repository and attach it there.

Issue #2719 created with sample files