Use grep to search the log file for the exceptions, use search patterns such as "ERR" or "ERROR" or exception codes etc. If the output is difficult to read, you may need to use a pipe to add more filtering. An example is pipe the output from the grep into sort [$ grep ERROR file | sort]. Maybe the lines in the log file are extremely long and you just need the first 120 chars of each line, then you would do this command [$ grep ERROR file | sort | cut -c 1-120]. If the log file is really large you may need to first split the file into smaller files, here is a link to the split utility:
Another issue to deal with is the log file might be compressed and there are many compression formats in Unix. Type $ file filename to find out if the file is compressed. If the file is compressed use the gzip, zcat or gunzip commands to convert back into ascii/txt format. Now the file can be search using your grep commands for your exceptions.
If the output from the grep is long and scrolls to fast for you to read, then you can pipe the output into a filter called "more", which will show you 25 lines of output from grep at a time, $ grep ERROR file | more.
If you need to save the output then you would redirect the output into a file which can be view with vi or emacs, $ grep ERROR file > yourfile. Then you can view the file in vi, $vi yourfile.