I didn't used to get this error when running an application launcher in 16.04. In 16.04 I recall having to install the Qt libraries, but I think that was off the main repository. Is anyone clued in on what may be going on here with 18.04?
When I launch the "launcher" for an older game I get the following:
[path to my file] libQt5Xml.so.5: cannot open shared object file
It seems that you simply need to install just one package:
That’s what I initially thought too. After having I “apt” installed it, the error persisted. :( Before giving up last night, I wondered if perhaps it was an environmental variable or something along those lines that was all ready set up in 16.04 and not 18.04.
Ubuntu 18.04 seems to have a problem (at least on my instance) with shared object files that apt/dpkg believes are installed, but the files are missing.
Use ldd to find out which shared object files are missing and reinstall them using apt. In this case, it's missing the package libqt5xml5, which you must reinstall. Installing will not work, because apt believes it is already installed, but you will find that the file itself is missing.
Keep doing this until all the missing shared object files are restored, and the program will launch.
Unfortunately, many of my apps are having the same problem. Something is not correct with the way apt works in Ubuntu 18.04.