If you used the debug tool to change render resolution (2912 for example like described by oculus) went into debug tool again and override render resolution to 0, or 2600 ... After doing that restart the oculus services and your link will work again. Tryed 2 days to get mine working again - it looks like the resolution tweak is written to registry or something else cause even full reinstall oder deleting folders didnt help me before .... now its working fine again.