Qt designer failed to save the file

appears when saving ui file:
This file contains top level spacers. They will not be saved.Perhaps you forgot to create a layout error

Please point out the mistake. thank you!
Xiaobai is here to thank the boss

Aug.24,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e45180-44b15.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e45180-44b15.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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