I recently migrated a 2.5 site to 3.3.6. I received the following error on my home page:
Error: 0 - DateTime::__construct(): Failed to parse time string (Friday, November 28, 2014 | 02:59:22 PM EST) at position 26 (|): Unexpected character
You may not be able to visit this page because of:
an out-of-date bookmark/favourite
a search engine that has an out-of-date listing for this site
a mistyped address
you have no access to this page
The requested resource was not found.
An error has occurred while processing your request.
It ended up being the rss feed that i had on the page which worked prior to the migration.
Over my head personally... I might suggest posting in the Joomla forums
SEARCH the forum first! These boards are rich in knowledge and vast in topics. This includes searching just the 'Solved' forums, using Google, and using ChatGPT