The application attempts to perform operations not permitted by the security policy. To grant the required permissions to this application, contact the system administrator or change the application in the configuration file.

Today, it suddenly appeared when maintaining the original project.

Security Exception

Note:ApplicationProgramAttempts to perform operations not permitted by the security policy. To grant the required permissions to the application, contact the system administrator or change the trust level of the application in the configuration file.

 

However, it was still working normally. Later I decided it was definitely a problem with IIS settings (I used iis7.5 + server2008), but I checked it online and did not say it was reliable. None of them works.

Later, I checked the data and finally learned why. It turned out to be a connection pool permission problem.

 

 

Solution:

1. Open IIS and select the connection pool.

2. Click to select Advanced Settings.

3. Select Process Model -- Select Identity -- and set NetworkService

4. OK