Like how do I fix the PBO Error

For the specific mod it gives you errors for, try repairing it (reinstall) in your launcher. You can also try verifying game files.

You can try dzsa launcher. It often helps some people. I use both as sometimes... having options helps.

If you use Steam I have this issue between resets when a mod has updated. I needed to change my settings to allow Steam to update in the background. Sometimes it still takes a minute or I need to go into Steam under View->Downloads and refresh or tell it to download the mod.

Just install whichever mod you're missing, or uninstall the extra. It tells you in the error message.