Aqua Data Studio will hang if you try to open files with .PRC extension, while investigating further into this I came across the following:

 

Aqua Data Studio editors are a powerful tool for creating and modifying your scripts and other source code. Aqua Data Studio supports SQL, AquaScript, Text, HTML, XML, JavaScript and Java Editors.

 

https://www.aquaclusters.com/app/home/project/public/aquadatastudio/wikibook/Documentation22.3/page/120/Editors-Viewers

 

Since the product does not support this type of files the only workaround is to convert your Stored Procedures to .SQL files in order to be able to open them with Aqua Data Studio. Although, the customer's entire GIT repository has the .PRC extension for close to 10k stored procedures, so it's not possible for them to rename all existing objects and scripts.