After upgrade or uninstall BoostSolutions products, there might be some invalid event receivers left which will cause error messages as belows:
Event manager error: Could not load file or assembly ‘BoostSolutions.xxxx, Version=1.0.0.0, Culture=neutral, PublicKeyToken=15fd9ef9a2ec3a95′ or one of its dependencies. The system cannot find the file specified.
Solution:
The issue is caused that some invalid event receivers haven’t been removed completely.
Please see the PDF article.
Applies for: SharePoint 2013, SharePoint 2010, SharePoint 2007