I can build the plugin, put it in the correct folder, but Qt Creator fails to load it with the error "...uses incompatible Qt libraries (5.15.0)" or something similar.

I built the plugin with Qt 5.15.5, but Qt Creator is built with Qt 6.9.1. I assume that I need to compile the plugin with a higher version of Qt. But after compiling the plugin with Qt 6.9.1 and installing it by copying it to the designated folder, Qt Creator crashes without any clue as to why.

How can I get this to work? I followed these instructions, and tried to put the library in my Qt Creator subfolder lib/Qt/plugins/designer. My system is Ubuntu 22.04.

One thing I noticed is that my Qt Creator also has a plugin called libDesigner.so, but it is in a different folder. The QHexEditPlugin names its library libdesigner.so. I can see how on Windows, with its case-insensitive file system, this might cause problems. But it should be OK on Linux.