The database is updating: HowNet's database is constantly updating. If there is a great similarity between the analyzed papers and the contents in the database, more time is needed for comparative analysis.

Network congestion: During the peak period of duplicate checking, the duplicate checking system of HowNet may face network congestion, which will lead to longer analysis time.

Wrong paper format: If there is something wrong with the submitted paper format, it may also affect the smooth progress of duplicate checking, resulting in too long parsing time.

HowNet system failure: When HowNet duplicate checking system fails or is under maintenance, it may also lead to a long duplicate checking time.

It is suggested to wait patiently for a while, or try to resubmit the paper for duplicate checking. At the same time, it is suggested to check the repetition of papers in advance to avoid similar situations in the peak period.