XnView Software

That's a puzzler!
I hope you can keep up your patience - I'll show you what I tried and what I achieved in 6 screenshots.
1)
This I get when opening a jpg file in outlook (Xnview is my standard program for opening .jpg). Sometimes it closes immediately, sometimes I get to shut the crashed program ...

Problem is, I ALWAYS have the crash since this problem started.
I doubleclick the attachment (or right mouse > open), the file appears in XnView for a split second, and shuts down. Same in old mails, which opend properly then. I tried to catch the open XnView window during that split second via a ...

So, where would I find this folder?
I download all my email (from several addresses) to Outlook.
They get stored in the folder E:\Daten\_Outlook (I specified the folder years ago, don't remember how...).
There's the files Outlook.pst and archive.pst. About 5 GB each.
The attachments must be stored ...

Sometimes yes, sometimes no. It always happens, wether there are only jpgs or others as well (.pdf, .docx).
It even occurs when there is only one jpg-file attached. I checked right now.
---> I thought you are asking about wether there are other attached files in the same email.

I re-read your post ...

Hello, good evening!

I‘ve been using XnView for years, and it is my standard application for opening .jpg and .png files.
Until recently, this worked perfectly. A few weeks ago the following problem occurred in connection with Outlook (I didn’t change any settings, neither in Outlook nor in XnView ...