Sometimes Web Log Storming can't read some log file lines. You can see error details in this window by choosing Tools | Parsing problems.
When Web Log Storming detects an obvious format problem (i.e. when number of errors exceeds 5% of total lines), reading will be automatically canceled to avoid wasting time dealing with an unreadable file.
Reasons for errors could be different:
|□||Small number of individual lines are corrupted (due to server logging error, strange requests from robots, etc). In this case you will see stats as usual, but they won't contain these hits (in most cases it's safe to ignore these sporadic errors)|
|□||There's a slight difference from expected log file format (for example, different date format). Your stats will lack of significant amount of data or, more likely, you will get No data results|
|□||Log file format is not supported at all|
In second or third case, please use the Send for analysis button so we can inspect what could be wrong and release a fix, if possible.