I had been using EE 1.7 and I could always download a loaded image to check for a large size or formatting problem from the backend. Now with 2.5.5, I am not able to download the images or otherwise see what might be the problem. How do I find out what might be wrong with the images?
How do I find out what might be wrong with the images?
There could be one (or more) of several things going on. Here are some things to check:
Verify that you can upload an image to the upload directory in question. Content → Files → File Manager → click "Upload File" button and upload to your directory. If you succeed then your images are uploading just fine you may have another issue. If the upload doesn't work continue...
Verify you can synchronize the file upload directory in EE. Content → Files → File Upload Preferences → click the synchronize icon for the directory in question, then Submit on the following page. If you have trouble here, continue...
Make sure your path to this directory is correct in EE by clicking the Edit link on the File Upload Preferences page
Make sure the folder exists on the server and has the proper permissions (most likely chmod 777).
Repeat step 1 to see if any changes you made worked.
If a Super Admin can upload but another member group cannot, check the member group's upload permissions via the same File Upload Preferences.
This is not exhuastive, but should help you in locating most issues or ruling out the most basic of issues normally encountered with file upload issues.
I came across a similar thing this week.
A client had uploaded IMAGE.jpg and image.jpg and had chosen on to display in an entry. EE couldn't distinguish between them and no matter which was selected the uppercase image showed first. Servers (rightly) see them as two files - all paths being case sensitive.
However it appears EE 2+ doesn't see them as two images (in our case using a grid and file fields) so we've had to do some tinkering to get them to display (deleting or renaming then updating entry).
This dual naming issue with upper/lower case could be the reason possibly?