DotNetNuke module missing from page

Question

I have a a strange problem with nuke modules i've been developing for a nuke 4.8.4 site.

I have one module that just refuses to allow another module to be placed BELOW it in the same pane. Everything loads fine as long as it is the last module in the pane, but if you move it above the other modules, the others won't load.

I originally thought that it was something odd in the markup of the module causing it to layer over the others - but when I view source on the page, the other modules don't even exist in the source.

Has anyone seen this issue before, and if so, how did you fix the problem?

EDIT: We've built a dozen modules - and ONE module does this on my machine, but a DIFFERENT module does this on another developer's machine. On each machine, the module that is broken for one dev works fine for the other.

Another interesting thing that we've noticed is that in the case where ONE of these modules is on a page, the GetTabModules will return 2 rows for the one module, both with the same ModuleID.

Answer 1

We uninstalled & reinstalled the offending modules, and they work fine now. Must have been some sort of bug in the install process. I'm going to upgrade to 4.9.2 and see if we run into similar issues there.

Answer 2

This sometimes happens to us, especially on older sites, AND especially if there is a long history, possibly with the recycling bin filled with old/deleted modules. It will seem that we keep trying to move a module UP or TOP and it won't move compared to the others.

The problem is easy to see if you look at the database and can see that the Module_Tab record involved has the same sort order number as other modules on the page, OR that it has a null value and adding a +1 or -1 to NULL still returns NULL !

So for us the answer is always to perform the following steps to clear out your issues (and this can be done without accessing the database):

1. Empty the recycling bin, and then come back to the page
2. Move all of the modules out of the pane that they're in... so if they are all in the Content Pane, move them to a left or footer pane.
3. Then, IN ORDER that you want to see them on the page, add each one back to the Content Pane, one at a time.

This process makes their sort order clear/irrelevant and then adding each module back in starts a new ordering number from 1 to 2, etc and after that, all modules will work properly with the normal Up / Down move actions.

Answer 3

It sounds like your module code is blowing up DNN. I'd run the site with a debugger attached and step through the code that is instantiating the modules.