FOR SC:R 1.23 SUPPORT:
Make sure you are using the july 9th (or newer) version from here: Download list. You can unzip it and replace an existing install, or run it as a portable version from any folder.
If the starcraft path is not autodetected, configure the settings as follows: profile settings. Note: The autodetected path may be empty or display not found.
Set the custom path option and enter the path where you have starcraft installed. This is not the starcraft directory under my documents, most common case is “C:\program files (x86)\StarCraft”. It should include a “data”, “x86”, and “x86_64” folder among other files. Make sure to set the starcraft version to 1.23 or to autodetect in the profile settings. If your settings dialog looks like this: example settings, then you are still using an older incompatible version.
If you get an error message “Unable to access the CASC data!”, then the configuration is correct but the install is corrupt. You will need to scan/verify your installation using the bnet app.