FYI - we prefer .txt (clean) files - not PDFs (infectable).
Anyway, status 50 is a strange beast... it just means that something aborted... think of all the hundreds of thousands (maybe closer to millions) of lines of code... and when the code knows that something unexpectedly aborted... well, it knows... and so a status 50 gets flagged by the section of code that was waiting for a response... so do you see how the calling code that was waiting for response from the callee cannot know why the callee aborted/failed... and so all the calling code code can do is let us (you and me) know that what was called (the callee) aborted (hence status 50)
I feel the same whenever it happens to me too.
Anyway, what this all means in practical terms is that there can never be a simple "oh status 50 means go fix so-and-so." - it's just not that simple, and never can be, and never will be. It's a fundamental aspect of computer programming.
So, it's down to you, and all of us, when it happens to us, to undertake the first step... which is... find out what was calling what... did you see that? "what was calling what" and that is all this is ever about, what part of NetBackup called whatever other part of NetBackup - or most usually it is a device driver or OS component which fails unexpectedly.
All we need to do is be thankful that the code stack does actually unwind so gracefully such that it is able to let us know that the callee failed/aborted/simply-disappeared, and that the caller noticed. Let's not imagine how hard life would be if either or both sides of code (caller and/or callee) were to simply crash or stack dump or just simply core.
So, you, and I, we all of us already have everything, you and I and all of us, we all already have all the tools that we need to debug whatever it is that failed... and it's all in the manuals/documentation which has been shared with you a couple of times now.
Go for it! You can do it!!
Did you have a good look at the errors in your attachment? Like this one:
11 sept. 2019 17:08:19 - Info dbclient (pid=6048) CONTINUATION: -System detected error, operation aborted.
Have you checked any OS or SQL logs (as suggested in previous posts) on the client ?