I have just come across this error on the DNN Creative website.

You may find that after a while in Admin / Log Viewer. That the Log Viewer stops working and throws an error.

This is because the Log had used a character which it couldn't read and so threw an error.

There is a fix for this error at this post:

http://forums.asp.net/958474/ShowPo...spx#958474


There are 2 options for the fix:

To delete all of the entries in the log file by accessing your database and deleting all entries from the eventlog table

ie. use "delete from eventlog"

Or apply a fix to the core code.
 
Both fix methods are explained in the forum post.

- I opted for the method of deleting the content from the eventlog table, and was instantly able to access the log viewer again.

This problem has been fixed for the next release of DotNetNuke