# Problem: Your project contains discontinued modules or assemblies

With newer Sitefinity CMS versions, certain assemblies or modules are discontinued.

For example, Sitefinity Thunder is discontinued in Sitefinity CMS 11.0.

## Solution

Remove the discontinued assembly or module and all its references.\
Use Sitefinity VSIX as an alternative to Sitefinity Thunder.

Refer to [Deprecated capabilities in Sitefinity CMS](https://www.progress.com/documentation/sitefinity-cms/deprecated-capabilities-in-sitefinity-cms) for a complete list of discontinued capabilities per product version.