Allow me to chime in on this thread to assist you further, @JMaassen.

Beforehand, the reason why the Customer Care Team you spoke with offered to upgrade your subscription is because QuickBooks Desktop (QBDT) 2020 software will be discontinued after May 31, 2023. This also means you won't receive critical security updates starting June 1, 2023.

In your case, we can perform troubleshooting steps. First off, please make sure your QuickBooks Desktop is up to date as well. Then, let’s utilize the Quick Fix my Program from the QuickBooks tools to fix your QBDT. Before that, you’ll want to download and install the QuickBooks Tool Hub. Here’s how:

1. Close your QuickBooks account.
2. Download the most recent version of the QuickBooks Tool Hub, then save the file somewhere you can easily spot it.
3. Open the file you downloaded (QuickBooksToolHub.exe).
4. Pay heed to the onscreen prompts to install, then agree to the terms and conditions.
5. When the installation completes, click the icon on the Windows desktop to open the tool hub.

 Then, performs the steps below to repair your QuickBooks.

1. In the QuickBooks Tools Hub, select Program Problems.
2. Click Quick Fix my Program.
3. Retry installing QuickBooks.

Let me know if you have more concerns with any QuickBooks-related matters. Stay safe!

i have 2020 desktop pro, would gladly buy new desktop pro but intuit greed only want monthly payments

i cannot send invoices anymore, changed my email to google and it worked again 1x, then back to memory errors. called support, 2 hours and nothing, called again 2 hours trying everything other guy did and obviously same results. was told it would be escalated, and they were there for me and she was going to call me back with an answer. still waiting weeks later. called again got very rude person who told me my name was not right, yeah i know my name, told be the acct numbers i read off the screen were wrong, yeah NO.. told me i had not paid my subscription for online, don't have one, told since i did not pay they shut down email as it was online only now.  so what i am told is pay up or we are holding your business hostage.  i have had QuickBooks going back to mid 90's and used to buy new edition every year or 2.  i am 67 and cutting back on my work, no big company, no employees, no payroll, just income, expenses and sales tax. why would i want t pay QuickBooks  $504 a year to email invoices.  i would not spend that is stamps in 2 years.

this is a lie because i looked up the error and it has been around for years. I just want to email my invoices and statements, not run Exxon on my home computer.

@travellover 

You don't need to run any add-ons, correct? Install the trial version of QB Desktop 2022 or 2023 to isolate the problem.

One work around it to just print the invoices as a pdf and then email as an attachment via your regular email.

One work around is to just print the invoice as a pdf and then email as an attachment from your regular email account.