Things to note when creating a new Model class

Yesterday, I created a new Model class at work and tested it in the test environment without any problems. However, in the production environment, an error was reported. Since the paging class was called, the error message said: The _count() function does not exist at line 520. My idea is: first go to the production environment and check the specific error file, and find that the _count() function exists at line 520. Cleaning up the runtime still doesn’t work;

Yesterday, I created a new Model class at work and tested it in the test environment without any problems. However, in the production environment, an error was reported. Since the paging class was called, the error message said: The _count() function does not exist at line 520.

My idea is: first go to the production environment and check the specific error file, and find that the _count() function exists in line 520. Cleaning up the runtime still does not work; the next step is to check the permissions of the Model class file, and find that it is 644. The permissions of other Model classes are all 664, so changing it to 664 is OK.