Fatal error: Call to undefined function login_security_soft_block_validate()

I cannot reproduce the described problem. View tested scenarios:

Scenario 1:
1- Have module installed in your environment;
2- Disable the module;
3- Simulate login using a valid user and good password;

Scenario 2:
1- Have module installed in your environment;
2- Simulate login using a valid user and a wrong password;
3- Disable the module;
4- Simulate new login. Use the same user of the step 2 and use a good password.

Plase add more details about used settings and how to reproduce.