错误：输出例程没有使用全部 \box255

Question

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*}