我的页脚收到以下错误消息:
\begin{textblock*}{0.9cm}(3.5cm,9.25cm)
\raggedleft
{\usebeamercolor[fg]{title in head/foot}\usebeamerfont{title in head/foot}
\hspace*{10cm}{\textbf{IEB}\hspace*{0.5cm}\insertframenumber}}
\end{textblock*}
%\hspace*{0.5cm}
\begin{textblock*}{3cm}(2cm,9.25cm)
{\usebeamercolor[fg]{author in head/foot}
\usebeamerfont{author in head/foot}\insertshortauthor}
\end{textblock*}
%Nombre del curso
\begin{textblock*}{7cm}(-0.9cm,9.25cm)
\raggedleft
{\usebeamercolor[fg]{title in head/foot}
\usebeamerfont{title in head/foot} \titulo \insertshorttitle}
\end{textblock*}