# Unicode char' (U+301) --> References do not update

I have a problem within ShareLaTex. I get the following error message:

``````Unicode char' (U+301)
``````

I received it after adding references to my bib file. `U+301` seems to refer to ~ signs or accents. That makes sense since I tried to input some Czech names including accents on letters.

What is strange: by now I deleted all of the references that I had recently added as I suspected a problem in them. Still, the References will not update after compiling.

I am using the following specifications:

``````\documentclass[11pt,oneside]{report}
\usepackage[utf8]{inputenc}
\usepackage[backend=biber,style=bwl-FU]{biblatex}
\setlength\bibitemsep{1.5\itemsep}
``````
• Try to delete the temporary files, especially the `.bbl` and if that does not help also the `.bcf`. – moewe Mar 9 '16 at 14:19
• Since you are using ShareLaTeX here are a few pointers on how to remove temporary files there: How do you make Biblatex work in ShareLaTeX?, http://tex.stackexchange.com/q/284342/35864. – moewe Mar 9 '16 at 14:25
• You are my hero of the day ;) – Jenny Mar 9 '16 at 14:55
• @moewe -- since your comments seem to have answered the question, maybe an actual answer is in order. and an addition of sharelatex to the tags. – barbara beeton Mar 9 '16 at 20:34
• @barbarabeeton Done! – moewe Mar 10 '16 at 6:56

The evil characters still reside in the `.bbl` file (which is read by TeX when it prints the bibliography) even after the `.bib` was updated. A Biber run is required for these changes to propagate to the `.bbl`.
The Biber run, however, can only succeed if the `.bcf` file (which `biblatex` uses to communicate with Biber) is well-formed. If the LaTeX run had to be aborted due to an error, often the `.bcf` is malformed.
To make sure the problem does not appear you have to remove the `.bbl` and `.bcf` files and recompile.