Slitherine

When clicking on the link of the manual on the game menu, nothing happens. Where can I find the game menu elsewhere?

It will have the original version. So you'll need to update it from the Internet.
Please note that you'll only need the last update, as our updates are comprehensive.

then maybe you don't have a file associated with a pdf file type program, if you have no pdf type program on your pc, it won't get read, to try, manually go into where the game is installed, eg right click on the shortcut and left click open file location and look for the folder manuals, open than and double left click on any file in there, if it doesn't work, then you have nothing associated with that type of file and you need to either associate a program with it on your pc, or install a pdf reader, which are free

There are issues in Adobe Acrobat that sometimes prevent it from automatically opening the .pdfs directly from the launcher. This is apparently due to a known issue with Adobe Acrobat Reader which cannot be resolved at our end. Microsoft Edge is more likely to open it correctly.

You should be able to open it as suggested by Zakblood.

However, if you already tried to open it from the launcher, an aborted version of Adobe Acrobat may already be running on your system, which will prevent it from opening even directly from the folder. You need to shut down that process by going into Task Manager (CTRL-ALT-DELETE), click on More Details, then end any running Adobe Acrobat tasks you may find.