client updates everytime i start up my pc

So, from time to time my client keeps asking to update everytime i start up my pc, the temporary fix to this is reinstall the latest patch but then i have to do it again in about 2-3 weeks. Is there anything i can do about this permanently? I have the disc space required (around 500 GB) so its not the issue. The pop-up i get when i start the client is "league of legends needs to apply a required update this will happen in:" Any help is greatly appreciated. Also, the patch size is about 2.1 MB.