"Invalid" login in Exchange in iPhone

A couple of weeks ago, while in the mall...I suddenly got a prompt/alert on my iPhone that I can't login of some sort to my Exchange account and it's prompting me to put in my password. This is the 1st time to get this alert and even after I input my password more than a dozen times, it was still giving me that "Invalid password" in Exchange. I tried changing my password for my Google Account and it still gave me that error prompt.

After fumbling in Google for solutions (saw in a couple of support group pages that this is a common problem)...I was brought to Google Accounts page where there is this 2-step verification. What I did was, I went thru with the verification and I was given 10mins to log on to my Exchange (Google sync) account on my iPhone which I did and that SOLVED THAT PROBLEM.