Running a WordPress site is not hard but you will have to take time to perform maintenance and fix small issues that could lead to bigger problems down the road. Clean Image Filenames is a handy plugin that that fixes filenames with special characters, which could cause issues for some of your visitors.
This plugin deals with periods, commas, accent characters, and more. It removes special characters or converts them to a regular character. It works for images and other file types. It should also work with custom upload_dir structures.