Blank White Screen on Homepage - even after trying all known fixes

My suspicion has been that it's a server issue, but I have no real evidence for that other than the fact that most of us never experience it.

What plugins are installed?

Is there anything useful in the server's error log or the MODX error log?

I'm also going to second this being a server issue. Given all of the sites are running on the same host / general environment, it could be something with their configuration that is causing the problem.

You might check if they are using CloudLinux, as that has been known to cause problems with MODX. Their configuration could be limiting the resources causing premature failures.

Thanks for replying, guys.

I third this being a server issue and it's where all our searching is taking place. Our host (KnownHost) has been very helpful and quick to respond whenever we've needed them and they are more than willing to look into this matter on their end but they are also at a loss as to what it can be. All our non-MODx sites are running flawlessly.

The weird thing is that all our servers (6 of them) are with them. Four are running cPanel and two Direct Admin. None of the MODx sites on the Direct Admin servers have ever had this problem. As stated before, we're looking to get away from Direct Admin, though. I don't think the server control panel has anything directly to do with this (just an observation and not a causal thing), it's just there is something about how each server is configured. What that is is what we're trying to find.

The other four, the ones with cPanel, are (supposedly) configured the same. However, three have exhibited the issues, but in different amounts and the fourth, which is relegated as our production environment, hasn't had any issues. So, that is three with issues.

So, then I wondered if it was the amount of traffic that was triggering the problems, since the production server hasn't had any issues (little to no traffic except by us for site construction). But, I've ruled that out because it turns out some of our more higher traffic sites are on a server with fewer issues.

The other day, I printed out the contents of phpinfo.php files on each of the four cPanel servers and sat there, comparing each entry, line by line, side-by-side, trying to find something that stands out. The only thing I found different (and we had thought the four servers were configured exactly the same) was that one of them had eAccellerator missing. However, of the four, that one with the missing eAccellerator was one in the middle in number of issues. Not the worst and not the best. So, I'm ruling that out of the equation for now.

Patrick, I'm going to look into your CloudLinux thought. Thank you for that.

In the meantime, anyone else with any thoughts, I would love to hear it. [ed. note: waizen last edited this post 8 years, 8 months ago.]

No CloudLinux. It was a good thought, anyway. Thanks.

The plot thickens... You could try moving one of the sites to another host, and see if the problem persists. If you want I can provide you with a test account on one of our servers.

Only time I've ever had the white screen is when php errors are being hidden so make sure there not, is there any add-onns that are across all effected sites but not on the none effected sites as that could also be something to look at ?

My experience is that a blank screen usually means a php syntax or other error error in a processor, plugin, or language file -- often resulting from a PHP upgrade. When files with an error are 'included' MODX often just dies and the error doesn't make it back to the including code so you don't see it.

The first thing to try is disabling all plugins if you haven't already.

If that doesn't help, try the technique described here: http://bobsguides.com/blog.html/2013/05/22/debugging-cmps-a-horror-story/.

Thanks for helping out, folks.

Patrick: Thank you for your kind offer for a test account. I sent your offer up the food chain around here (the boss) and he said he would rather not, but thank you.

Bob: I understand and agree with disabling plugins while troubleshooting. My thought with this issue is that it is so darned intermittent and illusive that I cannot purposely reproduce on command. Therefore, I'm thinking that disabling pluggins will, yes, turn them off but not demonstrate whether they are problems in any way...no before/after effect resulting from turning them on and off. Maybe when I see an issue and before I clear the cache(?) I'll give it a shot; can't hurt.

Having said that, I did poke around at all the sites I built and refreshed my memory as to what components I used in each. Some seem to produce errors from time to time but otherwise behave (as seen through the error log through the control panel). Components like Redirector, Big Brother, phpThumbOf. While I'm suspecting phpThumbOf to be a cache troublemaker, it is not a common component I use within all the sites exhibiting whiteout/menu disappearances.

Components I use in all my MODx sites are the usual essential components: Wayfinder, getResources, TinyMCE, FormIt, FormSave, etc. But, I think of them as so tried and true that I'm not sure they can be an issue here.

The thing is that there is a huge mix-and-match of many components across many different versions of MODx installs, with some sites intermittently exhibiting this problem while others, on the same server, do not. And others on other servers (the before-mentioned servers running Direct Admin) never seem to exhibit any problems. And, this intermittent behavior really is that: at some times once a day...other times weeks go by. I came back from this weekend with all my sites working great. Still great today (Tuesday).

I'm tempted to request if any of you three guys (Bob, Paulp and Patrick) would be willing to take a quick look at one of my server's phpinfo.php file, see if anything pops out at you on a server configuration level (I could email you a link to one of the sites' phpinfo.php files on the server). Not to spend too much time, but maybe something pops out at a glance. I really do suspect server-level issues here because of the intermittent behavior of such different MODx builds (differing component installs and uses on differing MODx versions). Not to mention that not everyone who has built sites with MODx has even come across this problem, even though they may have used the same components as me. What really differentiates those who have and those who haven't, I suspect, are the servers and configurations/hosting companies we use.