I'm missing the vertical line at the right! What can I do?
\documentclass[twoside, 12pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\renewcommand{\baselinestretch}{1.5} % Uncomment for 1.5 spacing between lines
\usepackage{graphicx}
\usepackage{amsmath,amssymb}
\usepackage{epstopdf}
\usepackage[swedish]{babel}
\usepackage{natbib}
\usepackage{parskip}
\usepackage{caption}
\usepackage{enumitem}
\usepackage{longtable}
\usepackage{hyperref} % use for hypertext links, including those to external documents and URLs
\renewcommand{\deg}{$^{\circ}$}
\newcommand{\eg}{\emph{e.g. }}
\newcommand{\ie}{\emph{i.e. }}
\newcommand{\Eg}{\emph{E.g. }}
\newcommand{\Ie}{\emph{I.e. }}
\newcommand{\cf}{\emph{c.f. }}
\newcommand{\Cf}{\emph{C.f. }}
\captionsetup{width=.8\textwidth}
\begin{document}
\begin{longtable}{|l|p{80mm}}
\caption[Feasible triples for a highly variable Grid]{Feasible triples for
highly variable Grid, MLMMH.} \label{grid_mlmmh} \\
\hline \multicolumn{1}{|c|}{\textbf{Kommun}} & \multicolumn{1}{c|}{\textbf{Klimatanpassning}} \\ \hline
\endfirsthead
\multicolumn{2}{c}
{{\bfseries \tablename\ \thetable{} -- continued from previous page}} \\
\hline \multicolumn{1}{|c|}{\textbf{Kommun}} &
\multicolumn{1}{c|}{\textbf{Klimatanpassning}} \\ \hline
\endhead
\hline \multicolumn{2}{|r|}{{Continued on next page}} \\ \hline
\endfoot
\hline \hline
\endlastfoot
Arboga & \vspace{-5mm}\begin{itemize}
\item daf
\item asdf
\vspace{-5mm}\end{itemize} \\ \hline
Fagersta & \vspace{-5mm}\begin{itemize}
\item ad
\item df
\vspace{-5mm}\end{itemize}.\\ \hline
\end{longtable}
\end{document}
Best Answer
As said in my comment it is better not to use vertical lines.
Please compare the following two tables. I used your MWE and added the second table. I deleted some code in your MWE not needed for your problem and I did some pretty printing ...
MWE: