Typically if you are unable to create a report in Funnel it is due to one of the follow reasons:
The upload takes too long - report uploads are limited by a two minute timeout, if for example your report is very large or your internet connection's upload speed is low that could cause the upload to time out.
Something in your browser/software blocks Funnel from storing the report - e.g. an ad blocker or privacy plugin such as Ghostery or Privacy Badger.
Something in your network setup blocks Funnel from storing the report - e.g. a hardware traffic filter, firewell etc.
In case of the uploading taking too long, you would likely see a progress bar loading up to a certain point, before being replaced by an error message. This is an indication that your report is too large. The work around is to use a different network connection or in case that's not an option, reducing the size of your report by decreasing the date ranges used in widgets or by splitting it into multiple smaller reports.
If it's not a case of upload time out, but rather you get an error message immediately, you are likely affected by some sort of network error. There are a few actions that you can take in order to diagnose this, presented below. Ideally you should reload you browser window and try to create the report again after each of these steps in order to see if any specific action has an effect:
Make sure there are no Firewalls etc. blocking your network access to https://funnel-report.s3.amazonaws.com
Disable all browser extensions
Use Funnel in a browser window running in incognito/private browsing mode
Try the same thing in a different browser
If none of those solve your problem, please reach out and we will do our best to help you troubleshoot. Please supply operating system and browser used including versions, and if possible include attach the output from his browser's console.