After conducting several tests, I have found that including more than 58 characters in the [slug] parameter will produce the error:
I used ?path=understanding-inversion-of-control-dependency-inversion-pr === no problem (58 char)
I used ?path=understanding-inversion-of-control-dependency-inversion-pri === Error thrown (59 char)
I created get method to test the revalidatePath()
Problem detected on vercel
/api/revalidate?path=