Plagiarism Detector has a default timeout of 30 seconds for a single resource processing.
A failure may occur if it does not have enough time to process a resource.
Resource processing includes:
1. Download resource.
2. Extract plain text.
3. Compare it with the checked document.
1 and 3 stages are time consuming.
This error may be caused by:
1. Slow Internet connection (low bandwidth).
2. Resource overload.
3. Resource is big (large amounts of text).
If Plagiarism Detector fails to process a resource in the alloted time period it will increment special counter in the main window:

And a special warning will be displayed if more than 10 resources timeouted:

To resolve this problem you can try to do the following:
1. Make sure no other application is using your bandwidth, and if so - unload it (torrent clients, on-line films\music, games etc.).
2. Increase Resource Processing timeout in Plagiarism Detector:
Settings->Core Config->"Single Resource Processing Timeout" in seconds.
3. Decrease the number of simultaneously used workers for Resource Processing:
Settings->Core Config->"REP Threads". Set it to
1 thread.
4. Investigate the exact status of the resource in Web Browser.
5. If none of the above helps - contact us!