Excel Report Builder add-on is not functioning properly

I am using Creatio marketplace add-on for Excel reports https://marketplace.creatio.com/app/excel-reports-builder-creatio. First I tried it using a trial instance and it was working fine. But in a production instance I am not able to upload templates to the reports.

I have tried removing .jar and .apk from "File extensions DenyList" system settings. Also tried removing the add-on and installing it again. but still could not able to upload the templates. It is doing nothing when I click upload button and select the template.

Thanks in advance.