When I want to delete some files, it happens to show me the error below:
Commit failed (details follow):
Cannot verify lock on path
'the file name...';
no matching lock-token available
If you want to break the lock, use the 'Check For Modifications' dialog.
Please help me to solve it.
At least one of the files is locked. As the error tells you, use the "Check for Modifications" dialog, click on the "check repository" button and then find the files which have a lock on them. Then either remove, break of steal that lock.