File upload not progressing

I have just uploaded a shiny app. It depends on a html file being uploaded. It works fine locally. I have checked it on linux as well. However, when I deploy it to the shiny server, the file upload progress bar doesn't move. There is no error that is thrown. The app does have some errors before the upload of the file but it goes away once file is uploaded. Also my upload file is big, more than 50 MB (i have changed the upload limit in the code)