If you’re still having trouble, then post your kicad version and the exact text of your errors.
This helps with diagnosing the problem and triage.
Simply pasting those error messages in an internet search engine often leads to results.
There are also multiple ways to assign footprints to schematic symbols.
What happens if you hover over a symbol and then press “f” and click on [Select] ?
And followed your suggestions on Library management. Everything seemed right, but still not finding the files. Then I noticed that, for some reason, there was a quote character ’ in my paths.
I fixed this and now the footprints are loaded. Kind of embarrassing, but that quote character in the environment variable path was really subtle.
I am getting some “not found errors” now, listed here
The following libraries were not found:
switches.lib
relays.lib
motors.lib
transistors.lib
conn.lib
linear.lib
regul.lib
cmos4000.lib
adc-dac.lib
memory.lib
xilinx.lib
microcontrollers.lib
dsp.lib
microchip.lib
analog_switches.lib
motorola.lib
texas.lib
intel.lib
digital-audio.lib
philips.lib
display.lib
cypress.lib
siliconi.lib
opto.lib
atmel.lib
contrib.lib
valves.lib
I would assume you created this project in version 4 and are now trying to access it in version 5. I already posted a link on how to transfer projects further up. (The second link to be precise)