Lag in timeline, error when rendered

I've been having intermittent issues with just general playback on Pro CC 2017 11.1.2.The reason I'm not using the 2018 version is because along with others I also have unexplainable timeline lag there as well. Simple project so far, just two clips with luts and some effects added on.

Computer Info

OS - Win 10

Processor - Intel i7 7700HQ @ 2.8ghz

System Type - x64 operating system and processor

Memory - 16gb

Graphics Card - GeForce gtx 1050 4gb (version 388.71)

Project Info

Premier  Pro CC 2017 11.1.2 (22) build

One 6 second clip of 3840x2160 29.97p footage and one 9 second clip of 1920x1080 29.97p footage.

Total length was 15 seconds, two clips, and lag on both clips with the yellow render bar above it in the timeline.

Sequence settings were at 3840x2160

With the constant stubbornness of the clips lagging with playback I went and rendered them within the work area and got this error when it came to rendering the second clip. First clip rendered fine but it wouldn't render the second clip, and then premiere froze after the error popped up. Obviously Ive tried making new projects with these two clips as well as I have reimported them and tried to render and replace the clips.

Edit: It seems when I restart premiere, it plays the second clip that couldn't be rendered flawlessly with no lag the first time, then when it comes to the second time it lags badly in the timeline. Also now getting generic importer errors for when importing 1920x1080p 29.97 h.264 footage?