ISSUE
Users may encounter an error message related to a '.dll file' when using Cisco Webex on a Windows computer. The error reads: "Error writing to file: C:\Users\username\AppData\Local\Programs\Cisco Spark\api-ms-win-core-console-l1-1-0.dll. Verify that you have access to that directory."

RESOLUTION

To resolve the '.dll error' issue for Cisco Webex on a Windows system, follow these steps:

1. Press `Ctrl + Alt + Del` on your keyboard to open the security options screen.
2. Select "Task Manager" from the list of options.
3. In the Task Manager, under the "Apps" tab, find any running instances of Cisco Webex.
4. Right-click on Cisco Webex and select End Task to close the application completely.
5. Right-click the Windows (Start) button and select Run to open the Run dialog box.
6. In the "Open" text box of the Run dialog, type in `%USERPROFILE%\AppData\Local\CiscoSpark` and press Enter. This will navigate you to the CiscoSpark folder in your local AppData directory.
7. Delete all the data within the CiscoSpark folder. This action will remove temporary files that may be causing the issue.

Note: Before deleting the data, please ensure that you understand that these files will be permanently removed and that you do not delete any necessary system files. If you need more clarification, it is recommended to seek assistance from a technical support professional.

After completing these steps, try relaunching Cisco Webex. If the error continues, you may need to reinstall Cisco Webex or contact technical support for more help.

CAUSE
This error typically occurs when the system cannot write to the specified '.dll file' due to insufficient permissions or another process uses the file.