There is no document that will show that an upgrade wil fix the problem, until we know what the problem is, and even then, with status 13 being so 'generic' I would be surprised if it could be shown for 100% certain.
As per the TN above, there are many causes to status 13.
Once the cause is found, then if there is a known issue that shows it is fixed by an upgrade, then there may be documentation that shows this as a possible fix, but it is virtually impossible to say an upgrade will fix the issue, and it only becomes more likely an upgrade may fix, if all the other possible fixes for the issue are tried first.
It would also be useful to know if this client ever worked, and, if it did what changed around the time the problem started.
If the client did work, then I would suggest it is certainly not impossible that an upgrade would fix (depending on the cause) but the actual cause is 'less' likely to be NBU itself, as the code you are running before and after the problem started is the same.
Of course, it is not a bad idea to upgrade clients if possible, so you may wish to try this anyway.