I have the same issue. Log into the app and extensions with same password the web vault declines. Email/pass saved in the bitwarden extension and used to log in. Linux w/Firefox,Brave,Chrome. I use the web vault to check my reports after paying for the subscription, but can’t log in.
@themichealjohn Welcome to the forum!
As the other thread was an older thread – and you might experience a completely different issue – I moved your post into a separate thread.
And did you check if you chose the correct server region for the web vault? – The US/.com and EU/.eu server regions are not interchangeable, and you can only log in to the server region where your account was created on.
(the server selector is at the bottom of the page)
Both were tried and same error “Invalid master password. Confirm your email is correct and your account was created on vault.bitwarden.com.”
@themichealjohn Could you try to open a private/incognito window in one of your browsers and try to log in again?
Do you know for sure on which server region your account exists on?
If nothings works so far, you can also follow this guide: [Guide] "I can't login" - Some tips for login problems/issues
Same issue. I have exported my info via password protected json just in case. Nothing else is broke, just the web vault. Logged into everything again on a fresh installed system as well, just not the web vault. Unsure which region I registered with, but mostly like .com
Hmmm.
A very wise decision! 
(just in case: make sure, that that password is not only in your vault!)
Besides the “guide” I linked previously, I think I would recommend to also contact Bitwarden support.
You said you are able to log in using the browser extension?
If so, you can open the browser extension and click on the account avatar icon (colored circle with your initials) in the upper right corner (shown circled in orange in the screenshot below):
This will open the Account Actions screen, shown below. Please look at the account that is labeled “active”, and pay close attention to the email address as well as the server name (bitwarden.com or bitwarden.eu) shown in gray font just below the email address:
When you attempt to log in to the Web Vault, make sure that you use the exact same server, as well as the exact same email address (matching the server and email address shown in the browser extension’s Account Actions screen).
Confirmed bitwaden . com is the site in the accounts section and email matches. Same error. No issues with anything else (Android app, firefox/chrome/brave extension and linux app). Will assume my access is off somehow.
I was able to log into the webvault at one point as it gave me the option for login with device. I don’t get that option after my newest OS reload. I did change the site to Bitwarden Web vault and it sends a code into oblivion as the extension or apps don’t get the prompt.
You can’t login with device unless you have at least one prior good login using another method. The OS reload likely reset the data that allows Bitwarden to recognize a browser as previously used for logging in.
Solved, I think. Using Bitwarden to log into the webvault for Bitwarden fails. Hand typing it in, works.
What do you mean by this? Are you atteptping to “Log in with Device”, or are you using the Bitwarden browser extension to autofill your master password in the Web Vault login form?
If you meant using autofill from the extension, then you probably should investigate what’s happening there. – I just tried it with a test account. But at least on one occasion, autofilling the username via the keyboard shortcut lead to a wrong password autofill, as the last used credential didn’t change accordingly.