The hash shown at the bottom of your post indicated that your edit didn’t take, for some reason (this is the hash value that you get when the final iteration value is 1 instead of 2).
Yes. At the end of line 481, you should (originally) see “…1, 256)”. This must be modified to read “…2, 256)”.
When you have opened the modified HTML file in a browser, it may be a good idea to examine the source code of the page (e.g., using Ctrl+U in Chrome) to confirm that the change that you had made on Line 481 is still there. Then check that the “Master Password Hash” value is xeEM0qT2Ggke5xqd7P1qSitei7O4SE2l5UrKreMw9vk= (before you enter anything in the input fields of the form). If all of this checks out, then enter the number of kdfIterations from your log file, as well as your email and master password.
In any case, all of the above is just to make sure that everything makes sense, given your previous statement that the “Master Password Hash” didn’t match your stored keyHash (which doesn’t make sense). However, if dealing with the above is too much trouble, we can just skip this, and make the (now pretty safe) assumption that you have an accurate value of the master password as it existed on Saturday.
What I would like you to do, is to go back to Bitwarden’s Interactive Cryptography Tool (the original one, not the one that you modified), and type in the number of kdfIterations from your log file, as well as your email and master password. Then record the resulting value of the “Master Password Hash” (if entering your master password on a website that is not the web vault login feels sketchy to you — I wouldn’t blame you — then just save the HTML file on your computer, do not modify it, and open it in a browser after disconnecting the internet). Repeat the above after setting the “Client PBKDF2 Iterations” value to whatever the new value was that you hade attempted to set o Saturday; record the second “Master Password Hash” value as well.
Please send the two resulting Master Password Hash values to the tech support representative, and ask them whether they can check if your stored master password hash (in the database) matches either of these two values (after they apply the server-side hashing). @bw-admin - do you think they can do this for debugging purposes? Even if tech support is unable to disclose what the outcome was, performing this check could reveal whether there is a bug in the code (e.g., if one if the two hashes produces a match with what is stored in the database, then you’ll know that @BostonPete’s login credentials did not change, and that he should not get an error when logging in).