Undefined symbol when trying to run pass

Hello, I am trying to run a pass, but I get the following error.
"

opt: symbol lookup error: ./constraint_pass.so: undefined symbol: _ZN4klee9KFunctionC1EPN4llvm8FunctionEPNS_7KModuleE"

I am really not sure how to go about solving this. I thought I would reach out to the developers for some advice.

Thanks in advance,

You may use different versions of LLVM. The version of opt may not consistent with your pass.