Are you certain that you were using http://usegalaxy.org when accessing this tool previously? Here is a list of other public Galaxy servers. If you were using one of these, or perhaps a local that you have access to, then contacting them directly about server issues is the best path.
Alternatively, if you are simply checking to see if the tool has been wrapped for Galaxy, then I do not believe it has, or at least not publically in the Main Tool Shed (for use in a local or cloud Galaxy). If I am wrong, we'll post a correction.
UPDATE: Perhaps this is the publication you are referencing? Web-based analysis of (Epi-) genome data using EpiGRAPH and Galaxy. The tool was once integrated on http://usegalaxy.org, but that was several years ago (around 2010), and it is no longer supported.
Thanks, Jen, Galaxy team