Issue:
For some reason, the logo on the invoice PDF is not displaying in some orgs (see screenshot below). And this happens intermittently/randomly. We believe that the PDF rendering engine on the platform has some issues. We’ll open up a case with salesforce.

Workaround:
As a workaround please edit your invoice template as follows:
Important: this only apply to PDF invoices. If your invoices are included as part of the email body, then this does not apply to you.
Go to Payment Center Settings tab, then click Customize Invoice button.
In the window that pops up, click Advance Edit. This will bring you to the invoice template editor.
In the editor, search for <c:Logo />and replace it with <c:Logo pdf=”true”/>, as shown below:
<div class="header">
<table style="border-collapse:collapse;" width="100%">
<tr>
<td style="vertical-align:bottom">
<c:Logo pdf="true"/>
<div class="smallText">
{!$Organization.Street}
{!$Organization.City},
{!$Organization.State}
{!$Organization.PostalCode}
{!$Organization.Country}
</div>
</td>
<td align="right" class="titleText">
<apex:outputText value="Invoice"/>
</td>
</tr>
</table>
<hr class="lineStyle"/>
</div>4. Click Save.
Alternative solution:
Updating the logo reference to an absolute URL resolves the issue. An absolute URL includes the full Salesforce domain and can be rendered by external email clients.
Open the receipt email template in Salesforce.
Locate the image reference that uses a relative URL.
Replace it with an absolute salesforce link in this format:
<img src="https://yourDomain.lightning.force.com/servlet/servlet.ImageServer?id=XXXXX&oid=YYYYY" style="height:55px; width:auto;" />
Save the changes.
Send a test email to confirm that the logo displays correctly.
Example Used in the Fix
<img src="https://yourdomain.lightning.force.com/servlet/servlet.ImageServer?id=015V1000006Es8OIAS&oid=00DHo000001aHY4MAM" style="height:55px; width:auto;" />How to Retrieve the Correct Image ID
If you need to confirm the image ID used in a sent email:
Open the sent email.
Click the three-dot menu (More options).
Select Show original.
Locate the image URL in the email source.
Copy the id= value to use in your absolute URL.
