utf8_decode function

[bobblkabb]

system check is giving me an error message:
ImpressPages uses utf8_decode function included in XML library. Without it, file uploads won't work.
There's something mentioned about utf8 in the documentation but I couldn't figure out how to enable/acivate.

Running Ubuntu 16.04.2, php7, apache2, Impresspages 5.0.2

That's the how to I was using.

[maskas]

This error must mean, you have to have PHP xml library installed.