OvrStream hosts third-party OpenFX plugins. Sometimes there can be conflicts that prevent OvrStream from opening successfully.
On Windows, try renaming or deleting OFXBridgeB64.dll from C:\Program Files\NewBlueFX\Common, then try opening OvrStream again.
On Mac, delete OFXBridgeB.bundle from Macintosh HD\Library\Application Support\NewBlue\Common, then try opening OvStream again.
If the problem persists, please contact support.