This error is highly likely to occur when a computer experiences unexpected power outages or abnormal shutdowns. This is mainly due to the damage caused by the system database and index files not being closed properly. In fact, the destruction of database index files not only causes such errors, but also results in errors in any operation related to database sorting. For example, when reading a user card, it always displays "non local area card"; Cannot print reports; When collecting water fees, the bottom level always remains unchanged at the first time, and so on. To solve this problem. After installing the power sales system, first copy all database index files (with an extension of. CDX) to a CDX directory created on the hard drive as a backup. When encountering this problem, simply overwrite the index files in the DBF directory under the system directory (usually C: KFPOWER) with these backup index files. Re enter the electricity sales system and select "rebuild index" under "system maintenance" to restore the system. Of course, this can also be made into a DOS batch command and a shortcut can be created.