"README_Y.txt" from "LFS_PATCH_X_TO_Y.exe" contain following words:

Quote :

Installation :
--------------
A FULL version of LFS S2 ALPHA X must already be installed AND
TEST PATCH X37 must be installed before installing this patch
To install the PATCH :
1) Move or save the patch into your main LFS folder
2) Double click the patch to extract it to that folder
3) When you see "Confirm File Replace" select "Yes to All"
5) Now you can start LFS in the normal way
NOTE : You can tell if the version is correctly installed when you run
the program (LFS.exe). At the bottom of the entry screen : 0.5Y

Is it a bug ?

I think its just a rushed copy and paste from 'LFS_PATCH_X37_TO_Y.exe 's readme.'

If you already had the test patch X37, then its not a bug, if you were still on patch X / X10 then it is a bug... albeit nothing to major. Just a Typo.

I think it isnt

Where can I get X37? how can I find out which X I have? Yesterday I updated to Patch Y and now My S2 license is away. The program showed me "Path info changed" as I started first gone after updating. now I can race only the demo. Help me, please!

Quote from Quixx :

Where can I get X37? how can I find out which X I have? Yesterday I updated to Patch Y and now My S2 license is away. The program showed me "Path info changed" as I started first gone after updating. now I can race only the demo. Help me, please!

You need to unlock the game now that you have applied the new patch Y. Use your game password to do this from within LFS.

You can check your current version from the main LFS screen. (see attachment below).