This problem is caused by a Kaspersky security product, or by another product using a Kaspersky technology. To fix the issue, if you're using a Kaspersky product, please check your the product settings: in the 'Options' section, open the 'Protection' subsection, and the 'Compatibility' section. There you should find an option called

"Compatibility with the Self-protection from Programs"

Activate that option, restart your machine and the problem should be fixed.

Note: this problem can also be caused by similar software products by different vendors. In that case, please contact the appropriate vendor of your anti virus product and ask how to allow self protecting applications like TweakVI to work properly with your anti virus product.

If you are using an Anti Virus product by a different manufacturer, please note that some Anti Virus programs do use components of Kaspersky - to clarify this you should contact the manufacturer of your specific product and check if they are using Kaspersky components, and if so how to ensure compatibility with the self protection of programs (see above).

Unfortunately there are hundreds of security software applications available, and we are unable to list all those that do cause the issue, since we simply do not know which of those do, and which do not. We do know that Kaspersky is one of the products causing this, as well as several Norton (Symantec) products, but there might be others, too.

Unloading (not just disabling), or uninstalling any security related application will show you which is the one on your machine causing this.

Unfortunately we are unable to provide further help in relation to this issue since it is caused by a third party security software which is out of our control.