panelizer%3Auser%3A1%3Apage_manager/71/step2

I need to store lots of documents. They can be png, jpg, pdf and I want to display them as thumbnails linked to some way to display the file big enough to read. When I try any of the available options to see what they do the only one that works is a simple text link and all the rest give this error. I tried different browsers but no luck.

An AJAX HTTP error occurred.
HTTP Result Code: 500
Debugging information follows.
Path: /panels/ajax/ipe/edit-pane/panelizer%3Auser%3A1%3Apage_manager/71/step2
StatusText: Internal Server Error
ResponseText:

php.ini is

error_reporting = E_ALL & ~E_DEPRECATED

; Maximum execution time of each script, in seconds
; http://php.net/max-execution-time
; Note: This directive is hardcoded to 0 for the CLI SAPI
max_execution_time = 400

; Maximum amount of time each script may spend parsing request data. It's a good
; idea to limit this time on productions servers in order to eliminate unexpectedly
; long running scripts.
; Note: This directive is hardcoded to -1 for the CLI SAPI
; Default Value: -1 (Unlimited)
; Development Value: 60 (60 seconds)
; Production Value: 60 (60 seconds)
; http://php.net/max-input-time
max_input_time = 60

; Maximum input variable nesting level
; http://php.net/max-input-nesting-level
;max_input_nesting_level = 64

; How many GET/POST/COOKIE input variables may be accepted
; max_input_vars = 2000

; Maximum amount of memory a script may consume (128MB)
; http://php.net/memory-limit
memory_limit = 256M