When i enter multiple items on an invoice i get this error message "Transactions can have only one foreign currency at a time" but if its a single item it saves?

Thanks for these details, @userboosawlah05.  What you are describing sounds as if it may be part of a bug we are looking into.  I'd like to do some basic troubleshooting just to make sure this is the case:

1. Restart your browser.
2. Clear your browser's cache.
3. Add Intuit as a trusted site.

If this does not resolve the issue, the support team will be able to help you out. All you need to do is let them know that you suspect you are impacted by INV-50843

To reach out to QuickBooks Online Support:

1. Sign in to your QuickBooks Online company.
2. Select Help (?) at the top right.
3. Enter your concern, then select Let's talk.
4. Select Contact Us to connect with a live support agent.
5. Choose a way to connect with us:
   • Start a chat with a support expert.
   • Get a callback from the next available expert.

Let me know if you have follow-up questions on this or anything else within QuickBooks Online. Take care!