Here we have a strange fix, but one that has worked for some people. Before launching Discord, we would even recommend restarting the PC and Windows for good measure. Wait for the services to terminate and then reopen Discord from the desktop icon or the Windows Start menu, depending on how you have it set up.
We recommend doing this before attempting any of the other fixes below. To remedy this, close any lingering services linked to Discord. Occasionally, a previous Discord session may not have shut down correctly, leaving it more or less open in the background, causing issues when you try to relaunch the app.