Let’s try taking these one at a time and let’s start with the theme activation error. Your problem here is that you missed a step when creating your custom theme. Please see this codex article and then see step 5 in that article regarding the need to change the name of the localisation text domain. That will resolve the error message you are getting although – this should only show up when activating. It should be fine in use after that.

The actual issue I m trying to fix is in conjunction with limiting image sizes to 400px width on our forum. That in itself works fine. But when I click an image and it opens in lightbox it is still set to 400px.

I have to say I am not really sure quite what you mean here. If you are restricting images (and I assume you mean uploaded images) to a width of 400px then when using the popup enlargement it IS going to be shown at 400px. And any attempt to make that bigger is going to blur it horribly.

I assume I am missing something so could you explain further on this one point? And perhaps a link to an example on your forum (if guests can see it) and some more deatils of your image settings in SP…

Progress: I recreated my custom theme and ensured I changed spDefault to spMyTheme in spFunctions.php, that solved the error message. One down, two more to go.

Did you see my post above – or were we posting at the same time!

Indeed we posted at the same time.

To the image issue, I am uploading and/or linking to full size images. Here’s what I am doing: under Forum > Options > Content Settings > Image Enlargement I set ‘Use popup image enlargement’ and then I set ‘Thumbnail width of images in posts (Minimum 100px):’ to 400. So any image I post >400px will be resized to 400px and a little magnifier is added. If I click on that image it pops up larger but is still 400px and not the original size.

If I preview my post and click the image it pops up original size. After publishing the popup is always 400px.

I made sure now I’m using the latest copy of the default theme, then edited it slightly to create my own custom theme (I’m just changing breadcrumbs to flat view and adding Pinterest and Instagram social links).

What I noticed, and you can see that in the screenshot, is that a “?=400” is added at pop up. I don’t notice this here on the forum. Apparently the 400px scaled size is passed instead of using the original size (or no size attribute at all).

Note: I don’t use S:P’s image uploading option, I only post images that have been uploaded to WP’s media library or external images from Flickr and such.

I suspect that you haver another plugin installed that is performing a lightbox type effect and that this is messing with and taking over the display from the Simple:Press native popup. Is that a possibility -= and of so – could you deactivate it as a test…?

I had already deactivated all other plugins and switched to the default theme, cleared browser cache and Cloudflare cache. The issue persisted.

As mentioned when previewing a post the popup works fine, it shows the full size image. But once published it keeps puling the S:P resized version.

Hold on, I am trying it again and now it’s working. Looks like there is a conflict with Jetpack (it’s the only one I didn’t deactivate previously)…

Yup, it’s definitely Jetpack.

Mmm. It is something all the same. This “?=400” is not something we add – in fact we do not use any query variables for the image popup. So – something you are using there is scraping the post content and finding the image url and taking the current output as the dimensions whereas we show the thumbnail and load the main image on demand.

You can see this if you look at the html source being generated for this very page with your image at the top in post #1. It would probably be useful to compare this to the html source being generated for your own site. Can you do this?

To be precise, it’s the Photon module. That explains it. The Jetpack Photon module pushes images to the WordPress CDN for faster loading. It must interpret the way S:P resizes as the actual image and pulls that back over.

I nearly asked if you were using JetPack because it causes a large number of problems – not just with SP but across the board. It makes too many assumptions. Not sure what to suggest…

I’ve simply deactivated the Photon module for now. I am not a fan of Jetpack either due to needing to connect to WordPress.com. But I already have 40 plugins and don’t want to install even more for some of the features Jetpack already offers and does quite well.

On a side note my current theme also uses a lightbox and does not collide with Photon, i.e. it resizes images fine to the original size in a popup.

That leaves not being able to delete S:P themes. Did th eusual spiel again and deactivated all plugins (including Jetpack) but it didn’t help. Clicking delete doesn’t remove a theme.

Sorry – forgot that one. I will take a look and rtn some tests – it has been a while since I tried it!