How heavy the shader is doesn't matter, what matters is the computer's ability to parse the shader instructions... I have no clue how you play any game with integrated graphics... that is admirable... but I take that whatever the instruction is that is causing the error comes from the fact... that maybe one of those instructions is more modern? that is my only guess...
Looks like your graphics card was released in 2010, that is 14 years old... My outdated drivers were about 4 years old... It might be an issue with the age of your graphics card... what is the age of the current drivers you have?
Edit: From my research, your drivers could be from 2014 if updated... is this correct?