How to fix Cairo error 'error while writing to output stream'

[Meiting]

g <- file_summary %>% filter(beton_of %in% c("S1","S2","LU","FM")) %>%
ggplot()+
geom_boxplot(aes(serie,tau_max)) +
scale_color_manual(values=manual_colors) +
geom_point(aes(serie,tau_max,color=Versagen),alpha=0.3,size=3)+
ylab(expression(paste(tau[max]," [N/", mm^{2},"]")))+
xlab("Serie")+
my_theme
ggsave("./graphics/SB_boxplot.pdf",g,device=cairo_pdf,width=14,height=14,units="cm")
when i run this code ggsave(), it tells me cairo error 'error while wirting to output stream'. Dose anyone know how to solve this problem ? thanks very much!