The installation problem is related to a "file in use" error. Try restarting your computer, if it does not work you should download mod apk directly from LDplayer's browser (you can copy download page from your computer into emulator)Already did that the first time before, it didn't work, still giving me the same error. I already restarted the LDPLAYER and I have no running apps when installing but still the same error.
If nothing works I recommend you to start using Nox Player emulator.