Moodle 3.6 upgrade - Blank Page - 500 error

Moodle 3.6 upgrade - Blank Page - 500 error

by Jayden Tyronian -
Number of replies: 8

Hi all


We were running v3.5 successfully up until a few days ago when I kicked off the 3.6 upgrade.  I've done an upgrade prior with little issue.


However this time, I got into the upgrade screen as expected and move into the plugin screen.  One of the plugins had an issue so I clicked 'Cancel' on screen to go back and went to rectify the issue on my end (file wise) and refreshed the upgrade page... at some point it goes to a blank page.


I tried reverting just the plugins folder back to the default one but I still get to a blank white page with a the following error:

... is currently unable to handle this request.

HTTP ERROR 500


There is no listed error in the webhosts error logs and my host Tech Support were unable to resolve the issue from their end either.


What would cause this that may be a quicker resolution, or am I better to delete the files and reload the 3.6 ones from scratch and try the upgrade all over again?


Jayden

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In reply to Jayden Tyronian

Re: Moodle 3.6 upgrade - Blank Page - 500 error

by David Pesce -
Picture of Plugin developers
Try creating a blank lib/eventslib.php file in your moodle web directory. It should allow you to gain access to the Moodle web UI.


The issue stems from a change in 3.6 that removed this file. I've found it fixes issues with HSU Forums and the Flashcards plugins. I'd recommend sending a note to the plugin developer to alert them of the issue. 


If it's something like HSUForum, I'd recommend finding a new forum plugin as it hasn't been updated since 2016 and only "supports" moodle 2.9

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In reply to David Pesce

Re: Moodle 3.6 upgrade - Blank Page - 500 error

by Mohammad Yaseen -

Thank you for this. We had a similar issue after the upgrade, and your answer solved our issue. However, do you think that recreating an empty eventslib.php might have other complications on different parts or native plugins in Moodle?

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In reply to David Pesce

Re: Moodle 3.6 upgrade - Blank Page - 500 error

by Howard Miller -
Picture of Core developers Picture of Documentation writers Picture of Particularly helpful Moodlers Picture of Peer reviewers Picture of Plugin developers

Erm....

Firstly, the OP doesn't mention either of these plugins.

Anyway, the fix is NOT to create an empty eventslib file. The fix is to make sure any plugins you bring over to a new installation are the compatible version for the new version of Moodle. So...

1. Don't copy the new code over the top of the old (Moodle) code.

2. Get a list of optional plugins you have added from the Plugins Overview page before you start and make sure you install the correct versions for the new version of Moodle. 

Having said that, the OPs description does not lead me directly to any of these conclusions. 


OP - if there's no error in the logs then either (a) you're looking in the wrong place or (b) logging is broken. It's inconceivable that an Error 500 would not be logged at all. 

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In reply to Howard Miller

Re: Moodle 3.6 upgrade - Blank Page - 500 error

by David Pesce -
Picture of Plugin developers

Preparation is always recommended, but your comment doesn’t provide value to someone who is already in this situation. 

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In reply to David Pesce

Re: Moodle 3.6 upgrade - Blank Page - 500 error

by Howard Miller -
Picture of Core developers Picture of Documentation writers Picture of Particularly helpful Moodlers Picture of Peer reviewers Picture of Plugin developers

Ok - if we are going to be like that...

Unless you know something about the users situation that I do not, you provided a solution based on (at best) guessing what may have gone wrong. 

You will find that I tend to push back a bit against such solutions while not wanting to make users providing those solutions feel unhelpful.

I wanted to point out how good preparation (or just reading the documentation probably) for an upgrade can usually prevent such things happening. 

More generally, however, the correct way forward is to attempt to diagnose the problem rather than guessing at random solutions. Worse - this may lead to the OP creating an empty file, which only masks their real problem and thinking, "great I have fixed it". We know what human nature can be like wink


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In reply to David Pesce

Re: Moodle 3.6 upgrade - Blank Page - 500 error

by Debbie Unterseher -

This worked.  Thanks!! 

Creating an empty lib\eventslib.php file worked! Thanks!


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In reply to Debbie Unterseher

Re: Moodle 3.6 upgrade - Blank Page - 500 error

by Howard Miller -
Picture of Core developers Picture of Documentation writers Picture of Particularly helpful Moodlers Picture of Peer reviewers Picture of Plugin developers
...which masks the problem and does not fix it. You'll be back... wink
Average of ratings: Useful (1)