The PCM.daily DB Team presents the first update and bugfix for both the PCM 17 Expansion Pack and the PCM 17 Variants DLC. You should install the bugfix even if you only have the Variants DLC, and only extract the files contained inside of CM_Stages inside of your directory.
1. Download the bugfix from the Downloads section or with the link provided at the bottom of this post. A download manager such as JDownloader is suggested, especially if your internet connection is slow and you think the download might go on for more than a few hours.
2. Open the archive you downloaded. Extract the content of the "Program Files" folder inside the directory where you installed PCM 17. Generally, that's going to be C:\Program Files (x86)\Steam\steamapps\common\Pro Cycling Manager 2017, but if that's not the case, the folder is always the one where you can find PCM's executable, PCM.exe. When you're asked to overwrite/merge, press 'yes'.
3. Extract the content of the "Documents" folder inside your Documents folder. Generally, that's going to be C:\Users\*YOUR_USERNAME*\Documents, but otherwise you should be able to find it yourself pretty easily. When you're asked to overwrite/merge, press on 'yes'.
4. Now it's time to start the game. When you create a new game, whether that is Career mode or Pro Cyclist, One-off Race or Track, select PCMdaily EP 2016NC (to play with the national champions of 2016 and race rules of 2017) or PCMdaily EP 2017NC (to play with the national champions of 2017 and the UCI race rules that will be enforced starting with 2018) as your database.
4b. This only applies if you have only downloaded the Variants DLC and not the PCM.daily Expansion Pack: you just need to extract the CM_Stages folder inside of the main PCM Program Files folder and overwrite any potential files when asked.
5. You're set, enjoy! If you followed this guide, but you’re still having problems with the installation, check the FAQ on the PCM.daily forum. If your problem isn’t listed in there, ask any questions in the support thread on pcmdaily.com, in the PCM.daily Projects section - the same as this post.