Allow Promasters to add to the allowed file type list.
Currently this is blocked with no apparent reason why.
You must contact support to allow uploading other file types. This could be a Promaster configuration setting.

Thank you very much for posting your feedback. At this time, we will not be adding this request to the near-term backlog, as we are focused on improving our search and process variation capabilities and delivering sequential approvals. However, we reevaluate requests every quarter and will reach out if priorities change. Please keep the feedback coming as it is critical for our longer-term planning.
-
AdminKerry Hiki (Admin, Nintex) commented
Other file types can be added to Promapp but you will have to contact our support team to enable this.