Fix WordPress Critical Error

I'm seeking an experienced WordPress developer to resolve a critical error message on my website. The issue surfaced after recent updates, and I installed new plugins before noticing the error. Currently, the website displays a white screen with the message: 'There has been a critical error on this website.'

Key Requirements:
- Diagnose and fix the critical error
- Ensure website is fully functional post-fix
- Review and manage the new plugins to prevent future issues

Ideal Skills and Experience:
- Strong expertise in WordPress
- Experience with troubleshooting critical errors
- Familiarity with plugin management and conflict resolution
- Previous experience with theme and WordPress updates
- Website design

Please provide examples of similar work done. I possibly need someone who can be reliable ongoingly and create a better website altogether. The guy that was helping has been stood down from his business and I need someone who can help take over.