Error message after trying to get my last ANOVA boxplot

[OliviaRN]

For the script 6_AlphaDiversity and 6a_GlomeromycotaAlphaDiversity , I have this issue:

I was trying to get my ANOVA boxplot (For my Evolution Presentation) but this message appeared:

Error in boxplot.default(split(mf[[response]], mf[-response], drop = drop, : invalid first argument

Not sure why this is happening, I did not have any problem before to get my plots.

Pls could you help me?