Hi Eshaan! Thanks for posting in the Lucid Community. 

Can you verify that the file is able to be opened correctly in Visio? If a file is the wrong file type or has some other issue that makes it an invalid file we will not be able to import it. If you are able to open the file in Visio please try re-saving it to both VSDX and VSD file formats then importing those files to Lucidchart. Switching the file type can sometimes correct issues in the file itself.

If these tips don't help we would love to take a closer look at the issue. Would you mind using this form to submit a Support ticket? Please make sure to include the original Visio file (VSD/VSDM/VDX/VSDX file). Thanks!