I've moved your post into the CityEngine space. You will get a much better answer here as the GeoNet Help is intended for community help and feedback. I have also added in a few additional tags. You can see more
on the community structure, and what topics are under each space from the following documents:
When I have trouble with opening a Rule file in CityEngine, I switch to Notepad++ to open it and see if there is something in the rule that is inconsistent. However, if that does not work it might be best to start from scratch.
Thank you for the reply! Well, the rule file is contained in the rule folder by default. I think it's a sample rule. but, it seems there is no instruction for it. So I wondered how people use the rule file to their project. Can't you see any error when you open the file?
Not exactly sure what the issue is - if its a bad file, I'd try creating a new workspace - the ESRI.lib gets added by default to every one you create.
You should note that the rule file is referencing textures - images of each letter - and they are located in the assets->General->Text folder so if you are seeing the default UV image (uvtest.png) than this is your error.
When I open the text.cga file, there are so many errors on it, but I can't find the problem.. I also don't know how to use the rule to my project. I just don't know what is the text.cga file for....
Can you tell me the number of your build, as seen with red arrow in image below? Also can you post your version of the Text.cga file. Just so I can see if I get the same compiler errors that you are.
Well, I checked ESRI.lib file in three different machines which installed CE application respectively and still had errors. All error messages say "No such function....". I don't know where I can get a fresh copy of ESRI.lib. I could not find it on Resource Center. Do I miss anything?