Download and Export Problem with my excel files

Hello friends,

I have created one download link for download local dirve excel file ,download but when i open that file. file content was encoded or broken data. not open normally. what is problem

here is my code

<a href="/download/template.xlsx">click here</a>

Same Problem with my other code where i can export table daat in the excel but when i open the downloaded or exported file it will shows broken data.

like �a�*+������&ffffff�?'ffffff�?(�?)�?�"dXX333333�?333333�?U}$}�

Please anyone have idea about this issue. ? Is that code problem or my Operating system Problem. I have used the Ubuntu Mate 18.04

i tried reinstall the libre office but not solved the issue.

Note:- other excel open the normally, issue with downloaded and exported.