Then you should first tell us the project settings, the rendering settings and the media info - otherwise we can only turn the large glass ball. Here is a collection of what else could be helpful and interesting:
Then uncheck legacy AVC and HEVC. Put hardware decoding back to Auto.
See if it renders. If not, try disabling the plugins and try again. If it is a plugin causing the issue let Magix know.
Setting GPU acceleration to none isn't a big deal- just disables some preview acceleration (might be having issues with one of your plugins). Decoding and encoding via GPU still work with this unchecked.
For Resolve, the free version lacks hardware decoding or encoding so don't expect great performance.