Some "native" (i.e., compiled C/C++ code) extensions may just be broken on FW >= 5.8.x, as there have been some rather massive changes in the underlying system.
Otherwise, what @knc1 said.
If you're able to run KUAL, you should be okay. Just make sure you've installed the *latest* hotfix, as otherwise, on FW 5.10.x, being able to *launch* KUAL doesn't mean being able to *run* stuff with KUAL

.