bookdown adding abstract before the table of contents

[cderv]

@john.smith

LaTeX Error: Environment abstract undefined.

I think this is related to this question too

LaTex error Environment abstract undefined

I am trying to create a template for a bachelor thesis (with RMarkdown) for my students and I cannot add the "Abstract" parameter in my yaml document. More specifically, when I am trying to knit it to pdf, I am getting the following error message: " ! LaTeX Error: Environment abstract undefined. Fehler: Failed to compile _main.tex. ". In global options I have (Sweave - typeset LaTeX into Pdf: pdfLaTeX). Furthermore, I installed tinytex as follows: tinytex::install_tinytex() . Any help will be highly appreciated. Thnx a lot in advance

You may need to check template used... Which format are you using exactly ? pdf_book ?
Is this possible to share a book example ?