why has ios 8.3 affected my gmail account access?

If you have two-step verification turned on for your email account, you'll have to get instructions from your provider on how to set up your account on a mobile device.

I also have this problem. I do not have two-step verification turned on for my email account. The provider is Google, with whom Apple has a partnership whereby this should be a seamless thing - which it was, until lately. By provider, do you mean cell phone provider?

Did you ever figure out an answer to this?

Google has recently tightened the security of gmail accounts, requiring stronger passwords. If Google has an alternate email address for you they would have sent a notice about this to you, with instructions about what to do about it. As a first step delete your gmail account, reboot your phone, and add it back. If that doesn't resolve the problem consider installing the gmail app on your iPhone. It's really pretty good.

BTW, Apple and Google are fierce competitors; they don't have a partnership, and they regularly sue each other.

I have exactly the same issue - my company for better / worse uses corporate version of Google for its IT infrastructure. I was able to work around by not using iOS for mail / calendar but loading separate apps - I like CloudMagic for email and the Google calendar app is good enough for now. Google and Apple may fight but dragging customers through the mud along the way isn't a terribly enlightened approach to creating a loyal / sticky customer base.....IMO FWIW.

The problem is that Google changed their interface around the same time Apple update iOS, so it appears to be an iPhone problem when it is really a Google issue. One solution is to use the Google gmail app (I do). It's a nice app that works reliably. Otherwise, you probably have to delete your gmail account from the phone, reboot the phone, and add it back. If you have 2 factor authentication enabled for gmail you will have to generate a new app-specific password.

Deleting the account and adding it back worked for me. As originally, I added it as an Exchange account, using my full email address as the account username, specifying m.google.com as the server, and selecting SSL on with S/MIME off.

It loaded (finally), but now it keeps telling me that the password is incorrect.

Am having identical issue on iOS 9.02 using business gmail account. I'd send a question to gmail support for business accounts except that Google doesn't provide any. I blame both Google and Apple for not talking to each other more. If I'm seeing this issue, thousands of others are likely also seeing it.

Read the message right above yours.

Deleting the account on the iphone is not a resolution since I cannot get the iphone to register the account, I get flipped back to the register screen after clicking the Google accept. No Gmail account is created