I am attempting to pay an online payment to a vendor and the dropdown menu for which account to pay from will not do anything. Ultimately, I am blocked from paying.

Try opening your QBO account on any private/incognito browser.

Welcome to the Community space, @Troy37. I'm connecting to provide troubleshooting to help you process an online payment to a vendor inside QuickBooks Online (QBO).

When accessing the program via a web browser, you may notice changes in your company file's functionality due to temporary internet data. The usual culprit is the temporary internet data that the browser accumulated from past or recent browsing activities. You'll want to access QuickBooks using an incognito or private browser to prevent browser-related issues. Here are the shortcut keys to open one:

• Safari 11 or newer: ⌘+Shift+N
• Chrome: Ctrl+Shift+N
• Safari: Command+Shift+N

Once you're in, enter a bill for the vendor and pay it. Choose a bank/Credit card account to settle the bill. If you're able to proceed, clear your browser's cache. Refer to this article for the steps: Clear cache and cookies to fix issues when using QuickBooks Online.

You can also use other compatible browsers if the issue persists. Refer to this article to see the list of compatible browsers in QuickBooks Online: Other browsers.

Also, I recommend contacting our Customer Care Team regarding being blocked from paying a vendor using the online option. This way, they can check your account and help you get through this as soon as possible. Refer to this page for more information: Get help with QuickBooks products and services. 

On top of that, I'm adding this article to help you learn more about how payment processing works inside the program: Learn about QuickBooks Bill Pay for QuickBooks Online.

I'll always be around to extend assistance in handling vendor payments inside the program or if you have other questions about QuickBooks. I'll make sure to respond as soon as possible. Keep safe.

Thank you for replying. I did try using an incognito browser and then, for good measure, I cleared the browser cache. When neither of those options worked, I tried another computer where I had never used quickbooks, and had the same issue. I have been paying our vendors once a month this way and never experienced this problem before.

@Troy37 

Consider using Melio as a backup option to sync with QBO and pay your bills. You can also get cashbacks.

https://quickbooks.intuit.com/learn-support/global/manage-suppliers-and-expenses/re-pay-bills-online...

I appreciate your efforts in exploring different troubleshooting steps, Troy37. I'll connect you with our Live Support team, who have the right tools and expertise to address this issue and offer the appropriate assistance tailored to your needs.

We receive a similar issue regarding this matter. However, other users encounter specific errors. If in case you encountered the error message "something went wrong", I recommend contacting our Live support team to further investigate the issue. They have the necessary tools to determine the primary cause and can offer screen-sharing sessions to help you navigate the program while addressing the concerns.

Here's how:

1. Sign in to your QuickBooks Online account.

2. Select the Help (?) button.

3. Select the 'Assistant' tab to get help from QB Assistant, or select the 'Search' tab to enter your question and find help articles.

For instance, you can send a screenshot or reply with the details of the error if you encounter a different one.

Meanwhile, I'm adding this article to help you ensure that your data and transactions are correct: How to view and edit vendor transactions in QuickBooks Online.

Moreover, visit this reference to check the payments you made to your vendors: Run a report with vendor totals in QuickBooks Online.

You can count on me to be here in the Community space, eagerly waiting to help you with any questions or challenges you come across. I'm here specifically to help you and always ready to lend a hand.