Whenever I come to the forum these days, the front page has at least one or two threads dedicated to people struggling with book covers, whether it's how to upload it, how to change it, or etc.
It's not that hard people. Let's address these issues:
1) Why is my book cover not uploading?
Well, that's probably because your book cover doesn't fit what Webnovel requires. Webnovel has very specific (& clear) requirements for your book cover, and they list it very clearly under the space where you can upload your cover.
Your cover MUST be EXACTLY 600 px in width, 800 px in height, no more than 5 MB, and in JPG format.
If your cover does not fit any of the three listed above, it's not going to work.
So... how to fix this issue?
Simple: make your cover fit those guidelines.
If you found an image that's not exactly 600x800 px, make it that way. Use something like https://imageresize.org/ and resize/crop your image! The site above also has functions to optimize/compress your image to make it less than 5 MB if that's the case (i.e... here) and it also has image converting functions to change your file type from whatever it is to JPG.
You don't have to own Photoshop or be a graphic designer to be able to do some basic editing like this. Searching online will give you more than enough results.
2) How do I change my book cover?
Changing your book cover is another simple thing that clicking around for a while will lead you to the results.
Go to Novels > Explore > Settings (should be a gear icon in the top right corner) > Press to upload book cover.
Again, make sure your new cover fits the guidelines of 600x800 px, less than 5 MB, and JPG.
3) How do I get a book cover?
Either make one yourself, or get someone to make one for you.
On the Webnovel forum, there are currently two threads dedicated to getting you a cover.
Free covers for your stories! by yaoyueyi (me)
Free Covers For Your Stories! by silentscarlettt
Just go to one of the two threads and request! (If they are open! Make sure to read the original post on the threads/any recent posts to see if they are open or closed. Do not request if they are closed-- as the owner of one of the threads, I can tell you that it is 100% frustrating to see people request when they are closed.)
You can also search around on other sites (e.g. wattpad, deviantart) to see if there are any people who are willing to make graphics for your stories.
If you want to make a cover for your own story, then there are programs both online and installable to help you finish the task. I personally prefer Photoshop CS6, but that costs money and there are good free alternatives too (just do some research on your own on what you can use) I've also seen people use online resources like https://www.canva.com/ which seems to work pretty well to get you a simplistic cover.
I also have this thread, Novel Cover Tutorial/Process, that gives some insight or inspiration if you want to look at how I make covers myself. There are plenty of tutorials online that are much better though, but I'm just putting that link out in case people don't want to do research themselves. (which is understandable... research is hard)
4) Where do I get images for my cover?
(or any search engines in general)
If you want to use images that don't belong to you, make sure that you're not using them for commercial purposes. Otherwise, there are copyright issues. (so, if you are going to get contracted, you can't use it) You can go on google and apply the filter "Labeled for reuse with modification" (Go to Images > Tools > Usage Rights > Labeled for reuse with modification) to get images that you CAN use commercially too.
There are sites like https://unsplash.com/ and https://pixabay.com/en/ if you want even more images.
That's about all the common questions and answers I can think of for now. If there are any more questions that you may have, feel free to leave them down below. I will do my best to answer them! (just please stop spamming the forums with threads about the same repetitive questions of "book cover blablabla")