Rainey

What you're referring to would be a CEL (Check Engine Light) which does indicate an error, not a warning... In that event then yes, there is something wrong that needs attended to.
What Death is referring to, in the case of it being a warning rather than an error, would be more like the log that your ECU (Engine Control Unit) of your car keeps to monitor system functions regardless of malfunction or normal operation. I.E.: "Your modified exhaust is not supported by the stock ECU configuration but still functions fine and within spec: let's keep a log of that just in case someone is curious."
What you have to understand is you are modifying the game from it's original intended function, with that is the inherent risk that the game itself is going to give you warnings that it would prefer things a certain way; not that the warning is necessarily breaking anything or affecting performance.
You said yourself that you are not a developer, in that case if I were in your shoes I would probably just listen to what the developers are saying and disregard the warning. I believe there are even ways to turn off verbose warnings if you don't want to see nonessential warnings such as this.

Your images are likely hosted on IMGUR or a similar website that restricts the amount of requests that can be made which is preventing them from showing, try changing where you host your images and see if that helps.