It is not recommended to upgrade the individual services by replacing the jars. I don't think jar replacement is alone enough. Looking at the trace it looks like the python scripts got changed. You can try updating the bin files "/usr/hdp/current/phoenix-client/bin/" (phoenix_utils.py file must have updated in Phoenix4.14) with the 4.14 ones from apache and see if that works.
P.S: Even if the above works, I don't recommend using this setup as we don't know what other issue you might encounter in future. If you want to move to newer version of phoenix do upgrade to HDP3.0 where you can use Phoenix 5.0.