Background

While trying to open AECOsim Building Designer, the program is failing with exception error. On investigating the exception error, application error code 0xc0000005 is displayed.

Steps to Accomplish

Exception error 0xc0000005 happens when the program, i.e., AECOsim has attempted to access a memory that it shouldn't. This error can occur due to many reasons. Following are a few of them:

• Both old and new versions of the application are installed.
• Incorrect system hardware configuration.
• Low memory or damaged RAM.
• Virus/Malware infection.
• Corrupt Registry entries.
• Data execution security feature (DEP).

Before we begin troubleshooting this, please check the minimum required system profile of AECOsim Building Designer V8i SS6 against your system configuration. If latter is as same as or more than the recommended, then we can move on to the next steps.

1. Basic Troubleshooting
To begin troubleshooting, please start with a system scan. Please run a full scan of your computer with your anti-virus program. After that, please make sure that you have all the Windows updates installed. Try running AECOsim after that. If the issue persists, we can move on to the next steps.
Check to ensure that all installed programs installed on your computer are updated. You specifically need to make sure that a program you attempted to launch before the error occurred is upto date. Re-launch the program to see if the error is resolved.
If the issue persists, if you had recently installed any new hardware, please check if un-mounting them helps. If not, please check if the hardware drivers are up-to-date.

2. Repair Corrupt System Files
Regular installation and un-installation of applications on your computer can be a cause of various problems including corruption of system files. Repairing corrupt files can be very helpful in resolving error 0xc0000005.
The following procedure relates to Windows 10 OS, but you can perform in on any version.
Press the combination of Win + X keys to open Power User Menu.
Select “Command Prompt.“
Type “sfc/scannow” in the command prompt before pressing ENTER.
The scan will automatically start running. Give it time to complete to report its findings. Now, Check and see if this solves 0xc0000005 application error for you.

3. Disable Data Execution Prevention (DEP)
The DEP is a set of security features that checks computer memory as one way of protecting your computer from virus. It can be the cause of the error if some installed programs are compatible with it. Disabling it temporarily can easily resolve the 0xc0000005 error.
Press the combination of Win + R keys.
Type “sysdm.cpl” in the open Run Box before pressing OK.
Click on the “Advanced” tab on the resultant system properties window that appears.
Go to on “Settings.“
Now, Click on the “Data Execution Protection” tab on the resultant performance tab window.
Select “Turn on DEP for all programs and services except those I select.“
Click “Add” before clicking on “OK.”
After that, Click on “Apply” then “OK” to effect the changes.
Close all windows now and check if Exception Error 0xc0000005 Persists. If it is still there, move to next method.

4. Reset Windows Internet Explorer Settings
The Internet Explorer security settings can be the cause of error 0xc0000005. Resetting the same can be helpful in determining the error. Just access the search box and type “inetcpl.cpl” in the box before pressing ENTER to open up Internet Properties. Click on the “Security” tab and reset everything to default.
Simply Resetting Internet Explorer settings may fix 0xc0000005 Error message for you. Its worth a try.

5. Disable Proxy 
Like with Internet Explorer security settings, your computer system proxy settings can also cause error 0xc0000005. Disabling the same can help to resolve the error.
Press the combination of Win + R key.
Type “cmd” in the Run box before pressing ENTER to open the command prompt.
Now, Type “netsh winhttp import proxy source = ie” in the prompt before pressing ENTER.
Read the resultant message. The message may relate to an error in writing proxy settings, which denies you access. This only means that you need to disable the proxy settings.
Launch Internet Explorer.
Click on “Tools” before opening up “Internet Options.”
Select “LAN Settings” on the connections tab.
Now Select “Use a proxy server for your LAN.”
Type address of the proxy server in the open “Address” box.
Next, Type the port number. (j) Click “OK” to effect the changes.

6. Perform System Restore
You can try the following method for a manual update.
Start your computer and log on as an administrator.
Click the Start button then select All Programs, Accessories, System Tools, and then click System Restore.
In the new window, select "Restore my computer to an earlier time" option and then click Next.
Select the most recent system restore point from the "On this list, click a restore point" list, and then click Next.
Click Next on the confirmation window.
Restart the computer when the restoration is finished.

7. When all else fails, as a last resort, Uninstall/Reinstall the software, may correct this error.