I'm currently experiencing a great issue on my site. I've encountered it in two separate ways but with the exact same result.
- I've installed an extension, but when I try to remove it the site is destroyed and I can't see the backend (or sometimes I can see only text) and frontend gets messy (see image).
- I went to Payment methods > Bank transfer > instructions and changed some of the text, but the site was compromised in the same way as stated before.
I've created a duplicate of my site and deployed it on a subdomain for testing, but I couldn't reproduce the error. I'm using a copy of the same database and of the same folders, so every problem should be here as well - right?
I've asked my server provider and it isn't a permissions issue. They've told me that the problem (for the payment methods) is that once the changes are saved the link is modified with no " / " at the end. For this reason they've told me that the issue is with my Magento installation. However, the error is not reproduced on the test site, as stated.
What's going on here?!
EDIT: I've forgot to state that my site is currently fine, I've restored an old backup, anyway the problem remains if one of this two things are done.