Thumbnails not generated for any image > 1mb

Silverstripe Version: 3.7.0

Question:

I’ve just upgraded a site for security purposes from 3.1 to 3.7.0. and noticed that some of the images stopped appearing (on website and within Silverstripe). It turns out that it will no longer generate a thumbnail for any of the larger images. I can upload a new small image <1mb and it works fine - but if I try a larger one it accepts the upload (and the image goes into the assets folder) but no thumbnail is generated (and no error message shown)

I’ve flushed cache and run the tasks Clean Image Manipulation Cache and Regenerate Cached Images Task but it didn’t help.

Some details from phpinfo() are below - if anyone has any ideas or can point me in the right direction for fixing this I’d appreciate it.

The client has it on a GoDaddy shared hosting account (Economy Web Hosting Linux) and no access to PHP settings that I can see. I think it will read a local php.ini file though.

|max_execution_time|30|30|
|---|---|---|
|max_file_uploads|20|20|
|max_input_nesting_level|64|64|
|max_input_time|60|60|
|max_input_vars|1000|1000|
|memory_limit|64M|64M|
|open_basedir|no value|no value|
|output_buffering|no value|no value|
|output_encoding|no value|no value|
|output_handler|no value|no value|
|post_max_size|33M|33M|
|precision|14|14|
|realpath_cache_size|16K|16K|
|realpath_cache_ttl|120|120|
...
|upload_max_filesize|32M|32M|
|upload_tmp_dir|/tmp|/tmp|
|user_dir|no value|no value|
|user_ini.cache_ttl|300|300|
...
|GD Support|enabled|
|---|---|
|GD Version|bundled (2.1.0 compatible)|
|FreeType Support|enabled|
|FreeType Linkage|with freetype|
|FreeType Version|2.3.11|
|GIF Read Support|enabled|
|GIF Create Support|enabled|
|JPEG Support|enabled|
|libJPEG Version|6b|
|PNG Support|enabled|
|libPNG Version|1.2.49|
...
|imagick module version|3.4.3RC1|
|---|---|
|imagick classes|Imagick, ImagickDraw, ImagickPixel, ImagickPixelIterator|
|Imagick compiled with ImageMagick version|ImageMagick 6.5.4-7 2014-02-10 Q16 OpenMP http://www.imagemagick.org|
|Imagick using ImageMagick library version|ImageMagick 6.5.4-7 2012-05-07 Q16 OpenMP http://www.imagemagick.org|

Ok this seems to have solved itself - the only thing I can think of that might have fixed this is that I removed the code below from config.yml and perhaps it took time to recognise this:

GDBackend:
default_quality: 90