Glad I found your question... as a newbie, I thought the "technical difficulty" was either a) the file upload to Adobe or b) the something about the jpeg not being read by them!
Horrible experience right out of the gate with Adobe Stock. They need a way more defined list of rejection reasons if I am going to contribute. I guess I'll check back next year to see if they are more informative. I don't feel like playing a guessing game with this.
No trouble to check back next year, but the rejection won't be more specific by then. I have even the feeling that it got less specific. The biggest mistake that beginners do is to assume that it is in Adobe's interest to point out specifically your errors in your pictures. But the Adobe interest is to get the pictures approved as fast as possible. But as all moderations are done by humans, there are differences in what one moderator sees or not.
So this is the deal: perfect or near perfect pictures pass. Pictures with some defects may or may not pass. WHen they not pass, they will get an error tag attached. That error tag is very often technical issues. You can then look into your picture and try to find them...or you post here, and some experienced users will give you advice on what may or may not be the cause.
In any case, you are bound to what Adobe accepts. And Adobe has an interest to accept a lot of pictures. SO when they get refused, it's nothing personal. It's because the buyers would complain afterwards...
If you are new to stock, you should consider these resources: https://helpx.adobe.com/stock/contributor/tutorials.html
Please read the contributor user manual for more information on Adobe stock contributions: https://helpx.adobe.com/stock/contributor/user-guide.html
See here for rejection reasons: https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
and especially quality and technical issues: https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html