Methods to Fix “Ac1st16.dll Not Found Error”

The ac1st16.dll file belongs to the Autodesk, Inc. ObjectdDBX program. In this article, we will discuss common ac1st16.dll errors and their solutions.

Ac1st16.dll Error

You may receive the following error when you try to run AutoCAD or after you have installed/uninstalled an application:

“A required .DLL file, AC1ST16.DLL was not found”

Cause of the Error

This AC1ST16.DLL error occurs due to one of the following reasons:

  • AutoCAD is unable to find the ac1st16.dll file on your computer even when the file is present on the hard disk.
  • The ac1st16.dll file is missing from your computer

Resolution Methods

Depending on the cause of ac1st16.dll error, use either of the following methods to rectify the issue:

Method 1: Correct the PATH statement

To resolve the ac1st16.dll error, ensure that the folder in which the ac1st16.dll file is located is correctly mentioned in the PATH statement.

The file ac1st16.dll is located in C:\Program Files\Common Files\Autodesk Shared

Ensure that the PATH statement contains the exact path that is mentioned above.

To check the PATH statement, perform the steps illustrated below:

  1. Right-click My Computer on your desktop and then select the Properties command.
  2. Next, open the Advanced tab on the System Properties dialog box.
  3. Next, click the Environment Variables button.
  4. The path to the folder in which the ac1st16.dll file is located will be mentioned in the Value column.

Go through the listed path carefully and check to see if it is incorrect. Look for a spelling mistake or an extra slash in the PATH statement. Use the Edit button to correct the path if it is wrongly listed.

Method 2: Reinstall AutoCAD

In case the above error is due to a missing ac1st16.dll file, uninstall and then reinstall AutoCAD to rectify the ac1st16.dll error.

To uninstall AutoCAD from your computer, perform the steps illustrated below:

  1. Click the Start menu and then click Control Panel.
  2. Next, double-click the Add or Remove Programs.
  3. In the Add or Remove Programs window, locate and select AutoCAD.
  4. Next, click the Remove button to uninstall AutoCAD.

Alternatively, to uninstall programs from your system effectively and quickly, you may use a reliable and trustworthy third-party uninstaller tool, such as Perfect Uninstaller.

Apart from a missing ac1st16.dll file or an incorrect PATH statement, other common causes of ac1st16.dll errors are:

Incompatible Operating System

AutoCAD 2004 is not compatible with Windows95, Windows98, and Windows ME. You may encounter errors in ac1st16.dll file if you try to run AutoCAD on these operating systems.

Malware Infection

Malware, such as virus, worms, and trojans deliberately corrupt your DLLs by injecting invalid codes into DLL files. To prevent ac1st16.dll errors due to malware infection, install advanced protective software, such as STOPzilla Antivirus and Spyware Cease and schedule regular virus/malware scans of your entire system.

Also, it is important that you ensure that your protective tools are regularly updated with the latest virus definitions and security updates.

Registry Issues

Corrupt or invalid registry entries may also lead to recurring ac1st16.dll errors. In fact, registry issues have often been found to be the root cause of DLL errors. To ensure that your registry stores only valid and required information, scan the registry regularly using a reliable registry cleaning utility, such as PCHealthBoost.

You can use this tool to perform custom registry scans to identify and fix DLL errors, such as ac1st16.dll errors.