The rtl100.btl is a system file necessary for Appraise-It to function properly. It is possible that the file was corrupted or deleted.
32-Bit Operating Systems
Click here to download a self-extracting .exe file which will restore the rtl100.btl file needed by Appraise-It. Simply close Appraise-It, save the .exe to your desktop and run it, then re-open Appraise-It. Please Note: You may need to right-click on the file and choose Run As Administrator for it to function properly.
64-bit Operating Systems
Click here to download a self-extracting .exe file which will restore the rtl100.btl file needed by Appraise-It. Simply close Appraise-It, save the .exe to your desktop and run it, then re-open Appraise-It. Please Note: You may need to right-click on the file and choose Run As Administrator for it to function properly.
See Also
Is my software 64-bit compatible? (includes a video showing how to check if your operating system is 32- or 64-bit)