You may have an old Comfort I system which has been upgraded to Comfort II. You need to use your old program which was done using Comfigurator 2 and convert it so that it can be read by Comfigurator 3 and to be able to write to the new Comfort II system, without having to rewrite the whole configuration again.
Follow the following steps
Read the old ccl file by File > Open, and select Files of Type ".ccl". Look for the correct ccl file.
Do File > Save As.. and select Save As Type .cclx. This converts a ccl file used by Comfigurator 2 to cclx format used for Comfigurator 3.
Your Comfort I system would have a different File System from Comfort II. A File system is the data structure that is used for the data in the Comfort nonvolatile memory (EEPROM). File systems for Comfort 1 are 17 for Comfort I Entry, 18 for Comfort I Pro, 24 for Comfort I Ultra. File Systems for Comfort II are 34 for Comfort II Ultra, 31 for Comfort II Optimum. The File system can be seen on the lower right corner of Comfigurator.
To convert the Comfort I File System to the Comfort II File System, select File > Convert File System to, and select the file system number from the drop down screen. For example to convert to File System 34 for Comfort II Ultra, select 34.
Save the converted file under a new name, with the extension cclx automatically appended.
Select Events > Responses and scroll through the list of Responses. Look for any Response in RED which shows an error, possibly due to a conversion error. If there is such an error double-click on the Response to try to clear it. If the Response is no longer in red, the error has been corrected. If not email the cclx file to email@example.com
The new file is now ready to be written to Comfort II.