Installing a library in a flatpak

[cxrvh]

You should try the same suggestions:

Flatpak Steam issue with Adobe Substance 10.1.0

Steam has own runtimes which you can try. You’ll have to run the software from Steam & probably force the runtime in the properties of the application (the procedure is the same as with Proton): Right click on the application → Properties → Compatibility → Force the use of a specific Steam Play compatibility tool. Select Steam Linux Runtime 3.0 (sniper) or 1.0 (scout) (at least 3.0 seems to provide libtiff.so.5). If this doesn’t work you could try: Report the issue to Valve (there should b…

If it does not work with the Steam runtime out of the box then you could also ask the mod developer if bundling what’s missing from the Steam runtime is a possibility.