Dan got a new cable box with Spectrum, but after a week he started to get an HDMI error because his connection has been "compromised." Scott says that the first thing to try is to power cycle the cable box. That will reload all the standard default settings. It could also be a faulty cable. So replacing the HDMI cable could solve the issue. Scott also says that being an older TV, the connection could be choking. Or maybe the HDMI connector could be failing.
Scott really thinks that Spectrum made a software change that isn't compatible with his older TV. He should try using the component input. It won't be as good, being an analog connection, but it could be his only solution short of upgrading his TV.