Which binary did you download? I have tested one from Urho3D 1.6 release and checked that it has the correct architecture and ABI, although I did not personally install the binary to test it.
$ file usr/local/lib/Urho3D/libUrho3D.so.0.0.248
usr/local/lib/Urho3D/libUrho3D.so.0.0.248: ELF 32-bit LSB shared object, ARM, EABI5 version 1 (SYSV), dynamically linked, BuildID[sha1]=7bcb509136d934562cd19b4fa28f81378418c9fa, stripped
If you are just getting started, download and install the correct prebuilt binary package is the quickest way to try. After that, learn how to build from source yourself by using the preconfigured RPI sysroot and cross-compiler toolchain (see urho3d.github.io/documentation/ … aspberryPi), i.e. build the software from the convenient of a normal Linux desktop host system and use scp to transfer the binaries to the device for testing. Believe it or not, it is actually much easier than try to figure out how to build the software using the device itself, though it is also supported by our buildsystem.