You can try the following solutions:
1. Reinstall the full version of word. Generally, the simplified version of word may delete some modules that are considered unnecessary by the simplified people, which will affect the acquisition of objects by the program.
2. Register the dll, ocx and other controls used in the directory where the mathematical tools are located. The command to register the control is regsvr32 *. Dll (* refers to the file names of those dll files).