For a couple days now I cannot access my site workflow inventory. (Gear > Nintex Workflow 2013 > Manage Workflow Inventory)
It hangs for a minute, then I get a Sharepoint error that isn't helpful ("Something went wrong").
I can access my list workflow inventory.
I can access my site workflow inventory on other sites I own.
This is the URL to the site workflow inventory that I cannot hit: hxxps://domain.net/site/subsite/_layouts/15/NintexWorkflow/WorkflowGallery.aspx
I do not have admin on this farm, but I am in contact with those that do.
The "Something went wrong" error can actually be helpful. If you click the "Technical Details" link in the error message, you will see a correlation ID and a timestamp. This information can be used by your SharePoint administrator to find messages in the SharePoint ULS logs relevant to your session. Any error messages in the ULS logs associated with your session may help you figure out what is causing the problem.
What version of Workflow 2013 are you running? There is a known issue with Nintex Workflow 2013 version 220.127.116.11 that is similar to what you describe.See here.
The fix is to upgrade Nintex to 18.104.22.168 or later.