Version 4.0.8xx "Object reference not set to an instance of an object."

[dandreat]

Greetings;

I'm experiencing an intermittent problem in 4.0.849 on Windows 7 Pro 64, though it is not unique to this version. I'm receiving "Object Reference not set to an instance of an object." messages and an associated failure to download / synchronize SOME of my groups MOST of the time.

I'm currently following 16 groups, some with little activity and others with tens of messages per day. Sometimes all groups will download, but most times only a few. I've tried starting PG Offline each time I want to use it and I've also tried leaving it running, sometimes for many days. There doesn't seem to be any significant difference in behavior related to time left running. Though sometimes when the application has been running for awhile, something will change and all my groups will download. I've noticed that groups which fail during "Refresh" will also fail when individually selected and using "Start".

For me, this problem seems to have been in many, if not all, of the versions which have been produced over the last year.

I'm interested in any insight to this problem, especially if there's something I can do as a user to work around it. And, I'm happy to share any additional information which might help solve this problem.

I'm thankful for this application and I appreciate all the work that has gone into maintenance and improvements.

Best Regards,

Dave
Erie, Colorado

[Wilson Logan]

Hi Dave,

 The object reference error is a bit of a catch all.

 Normally it'd be caught in a program and a better more explanatory error would be served to the user.

 We used to get it a lot because PGO used to try and get groups even if it wasn't logged in and the subsequent error that was

 " You are not logged in "

 turned up as the object reference error.


 As no one else is reporting object reference errors anymore, it would appear that this is a unhandled exception that is specific to your PC setup.

 In order to eliminate some possibilities can you install & try PGO on another PC or laptop which is using the same internet connection as your current PC/laptop.

Cheers,

 Wilson.




 

[dandreat]

Hello, Wilson;

Thank you for your insight and the knowledge that this error message could be reporting an issue with being logged in. Armed with this information, I decided to run a few more experiments before trying a fresh install on another machine (though, I expect that would have worked fine given what I have learned).

Though I didn't expect any problems, I decided to look at File -> Master Login. No problems there, but I decided to try re-entering User Name and Password. No change in download behavior from this.

Along the same line of thought, I selected a few representative groups (some which were updating properly and others which were not), then 'right click' -> Group Settings -> Group Logon tab and checked that Yahoo User was either (default) or my Yahoo User name, and re-entered the Password. I tried several combinations of not "messing" with the Password or Yahoo User, entering new ones, changing one but not the other, etc. Again, no change in download behavior no matter what I did here.

Before I explain my next experiment it's important to know that I've been using / testing PG Offline for quite some time now, including during the period when the "Object Reference not set to an instance of an object." message was very common. This was during the time when Yahoo and/or PG Offline was changing the way that "authorization" was working.

What is important here is that at some point during those days, you recommended that  File -> Options -> Workflow tab -> Skip authorization be selected. Long ago, I successfully ran with "Skip authorization" selected for several versions and over a period of weeks to months. I don't remember ever specifically clearing that selection, though at some point it may have been deprecated anyway and things just started working without it...

I decided to try selecting it again. Now here is where it gets interesting! I expect there may have been a "stuck" value in a preferences file or registry key. As soon as I selected "Skip authorization" and exited the tab clicking "OK", download behavior changed!

The download activity during either Refresh or Start (with a group selected) appears to now be working correctly! For the first time in a long time, I now see the messages

<timestamp> [group name] Logging in with account
<my Yahoo Login name>

for each group and the group messages are now being downloaded again!

When I later looked back at the File -> Options -> Workflow tab -> Skip authorization, it appeared unselected (and remains so). This is why I suspect that there was a "stuck" or corrupted field for that value, causing PG Offline to skip logging in before each group synchronization. It is still mysterious that some groups would synchronize without logging in, AND that the groups which would work and those that wouldn't changed and appeared somewhat random over time.

So, for now, all is well. I've exited and restarted PG Offline many times and the behavior now seems consistent. ALL of my groups are now synchronized, which hasn't been the case for a long time. If you have some users who are experiencing a problem like this, it may be worthwhile considering that a preference value may be "stuck" or corrupt.

So, I won't take any more bandwidth. As always, thank you for your help and insight! I'm back catching up on some groups which I haven't been following for months. And, enjoying PG Offline, of course...

Best Regards,

Dave
Erie, CO

[Wilson Logan]

Hi Dave,

 That was a good catch!  Well done!

 The reason you used to see some groups updating and not others was that some groups are public and do not require a login token to be set in your browser to be able to access them.

Logging in to Yahoo sets a token for the duration of the browser session and thereby Yahoo does not re-request a login for each private group.

In the past PGO would do a login for each group but by setting the 'Skip Authorisation'  flag it would login only once per session. I keep meaning to ask the developer to reinstate this function.

However, knowing all that would still not have made finding this problem much easier and you found it without that background information.

That was a good piece of detective work!

Cheers,

 Wilson.