I had the same problem and the solutions provided were not very helpful because manually reviewing hundreds and, possibly, thousands of Names is not something that is simple to do.  What finally made it so much simpler to find the errant characters in my QB lists was to use the Reports, Lists menu option to view all of the Customers, Vendors, Employees, and Other Names as reports.  When viewed this way any "unsupported" characters show up as garbled in the report output.  It turned out, in my case, that I had an accented e for a customer from Canada who has been in our QB for years.  When I changed the accented e to an "e" the error disappeared. 

Had I not seen the list of customers as a report, I would have never found this problem because I thought the error had to with something that had been recently added to QB. 

Hopefully, this is useful for somebody else.

Three different representatives today and they all have given me different reasons for this error.

I FINALLY FIXED IT! For months I was dealing with this issue. I followed all instructions and saw the single YouTube Video I could find on this issue. I was on a QB Chat and the person started going through everything I had done, I shared my screen and the chat was ultimately ended for some reason.

The second person on the chat had me go through all the same things again. She ultimately decided that the - symbol was causing the problem and that I would have to manually change every instance in which the symbol - appeared. I asked to speak to a supervisor. She told me there were no supervisors available. She insisted this would fix the issue, she sent me this very article as proof. When I quoted this article saying that an unprintable character is one not found on a keyboard, and that the - symbol is found on a keyboard she disconnected.

I called and spoke with a third person. She went and claimed to speak with her supervisor who she insisted assured her the problem was with the bank. She said I would have to login to my bank and edit each and every transaction name so that each transaction name would only have alphanumeric characters.

I hung up on her.

I then tried what the last person posted. I went to --> Reports--> List--> and then I reviewed all lists. On Customer Contact List I noticed that at the top of the list was a name that did not belong there alphabetically. I clicked on the name and learned that the name started with a (space). I deleted the space and everything worked as before. I am so very glad I did not listen to the QB reps and instead followed the instructions here.

this issue is still not done.  we have thousands of customer s and vendors.  we always used classic  bank feed mode. all worked fine. now BOA changed connection type and it requires advanced or express mode. and it doesn't load vendors, customer lists because  of those characters...I could not fine any tools to  fix it . it is Oct 2023 now.

Hi olegnay,

We want you to come across a different issue than this. I'm here to make sure we resolve your banking issue.

To start with, let's back up your company file, then update QuickBooks Desktop to the latest release. Once done, let's rebuild your data to make sure your company file is error-free. Here's how:

1. Go to the Window menu and click Close All.
2. From the File menu, click Utilities and select Verify Data.
3. Wait for it to load.

If the system prompts you with Your data has lost integrity error, let's rebuild the software. Go to the File menu again, click Utilities, and select Rebuild Data. Please check this link for additional details: Verify and Rebuild Data in QuickBooks Desktop.

If the same issue persists, I recommend reaching out to Bank of America's support team so they can guide you accordingly on fixing the issue.

For your future reference, refer to this article to add and match bank feed transactions in QuickBooks Desktop: Add and match Bank Feed transactions in QuickBooks Desktop.

Keep in touch with me if you still need more help with online banking errors. I'll be here for you. 

Thank you. Issue is not in BOA.data form BOA are loaded ok.  I cannot open express  mode of bank feed. or advance mode is opening but no customer or vendor list is available. and Express mode tell me that there is not supported character in my vendor, customer , or other  list names. this is why it is not opening.

how can i find which vendor , customer has  unsupported character?  our company file is 20 y.o there are thousands of vendors....

Hello, olegnay.

Thank you for reaching out to the Community. If you are experiencing issues with your QuickBooks Desktop, like missing data, it is possible that your data is corrupted or broken. To troubleshoot this issue, you can try the following steps: 

1.  Run the QuickBooks File Doctor tool: This built-in tool can help you diagnose and fix issues with your QuickBooks company file. You can access it from the QuickBooks Tool Hub or by downloading it from the Intuit website. 
2.  Verify and Rebuild Data: This is another built-in tool that can help you detect and fix data integrity issues. To use this tool, go to the File menu in QuickBooks Desktop and select Utilities > Verify Data. If QuickBooks detects any issues, it will prompt you to Rebuild Data. 
3. Restore a backup: If the issue persists, you can try restoring a backup of your company file. This will allow you to go back to a previous version of the file when it was working correctly. Be sure to create a backup of your current file before restoring a backup. 

On the other hand, to find which vendor or customer has unsupported characters in QuickBooks Desktop, you can use the following steps:

1. Go to the Customers or Vendors menu in QuickBooks Desktop and choose Customer Center or Vendor Center. 
2. Click the Excel button at the top of the list to export the customer or vendor list to Excel. 
3. Open the exported Excel file and select the column that contains the name of the customer or vendor. 
4. Click the Conditional Formatting option under the Home tab and choose New Rule. 
5. In the New Formatting Rule dialog box, hit Use a formula to determine which cells to format. 
6. In the formula box, enter the following formula: =IF(SUMPRODUCT(--ISERROR(CODE(MID(A1,ROW(INDIRECT("1: "&LEN(A1))),1)))), "Unsupported," "Supported") 
7. Press the Format button and select a color to highlight unsupported customer or vendor names. 
8. Click OK to close all dialog boxes. 
9. Save the Excel file and import it into QuickBooks Desktop to update the customer or vendor list. 

However, if none of the above steps resolve the issue, you can Contact QuickBooks support for further assistance. They can provide additional troubleshooting steps or help you repair your company file.

You can visit this thread whenever you have additional questions about unsupported characters. I'll be around to assist further. Have a good one.

YAY FOR YOU! IT WORKED!!!

Welcome to the community space, tockj.
 

We're glad to hear that the information shared above was helpful to you. We continually strive to improve our product to make your experience with QuickBooks even better.
 

You can always return here if you need help with anything else in QuickBooks. We'll be right here to assist. Best wishes!

File > Utilities > Export > Export IFF flies > do one type at a time

Open in excel (Flip Excel flies > all files)Covert as a tab delimited

Insert 2 columns Now B and C1st new column B 

Use the =Clean(<cell with the name in it>)  to remove special characters then use =B1=C1 to compare cells