I've just moved a site using 2.5.5 from my local setup to our hosting account under a sub-domain for staging but am having some odd issues.
At first the site is fine but if I visit the add-ons tab I get the whitescreen of death front-end and CP. I turned on debugging and got the following error
A Database Error Occurred Unable to connect to your database server using the provided settings. Filename: core/EE_Config.php Line Number: 211
Disabling extensions in config.php didnt help but if I change the database user (ie create a new user and update database.php) the site comes back fine.
Even with extensions disabled, if I try to access add-ons, I get the same routine…
I have a 2.5.3 site in another subdomain on the same server with no issues at all.
I have the following third-party add-ons installed: Assets 2, Matrix, CP Analytics, Field Editor, Freeform, Google Maps for EE, Low Reorder, NavEE, REElocate, Sitemap, Environment, Health Check, NSM Addon Updater, Low Alphabet, P&T Field Pack, Playa, Expresso, CE Image
The local install is running perfectly.