I am running into a similar issue you did when trying to run the bssr:
Error: Could not determine the BrainSuite atlas used for registration.
Please check the log file C:/Users/Fproessl/Desktop/BACL_Visual/4010WK/4010WK.svreg.log, and check if the subject directory is valid. If using a custom atlas, supply the path in the atlas= argument.
Do you remember how you solved this? I tried to rename the filepath of the .log file but it did not work…