SWFUpload 500 exception

SWFUpload 500 Error
Discuz Forum to change the WWW domain name BBS after the editor swfuplaod upload report 500 errors, but sometimes can upload normally;
At present, the basic elimination of PHP on the server problem, because changed to blank page is also the same error.
Has anyone ever met this problem? Ask for advice


swfupload log:

---swfupload Instance Info---
version:2.5.0 2010-01-15 Beta 2
Movie Name:swfupload_0
Settings:
upload_url:http://bbs.xxxx.com/misc.php?mod=swfupload&action=swfupload&operation=upload&fid=72
flash_url:static/image/common/swfupload.swf?preventswfcaching=1398395968643
flash9_url:static/image/common/swfupload.swf?preventswfcaching=1398395968643
Use_query_string:false
Requeue_on_error:false
Http_success:
assume_success_timeout:0
File_post_name:filedata
Post_params: [Object Object]
File_Types: *.jpg;*.jpeg;*.gif;*.png
File_types_description:image File
file_size_limit:5000
file_upload_limit:0
file_queue_limit:0
Debug:true
Prevent_swf_caching:true
Button_placeholder_id:imgspanbuttonplaceholder
Button_placeholder:not Set
Button_image_url:/static/image/common/uploadbutton.png
button_width:100
Button_height:25
Button_text:
Button_text_style:color: #000000; font-size:16pt;
button_text_top_padding:0
button_text_left_padding:0
Button_action:-110
Button_cursor:-2
Button_disabled:false
Custom_settings: [Object Object]
Event handlers:
Swfupload_preload_handler Assigned:true
Swfupload_load_failed_handler Assigned:true
Swfupload_loaded_handler Assigned:false
Mouse_click_handler Assigned:false
Mouse_over_handler Assigned:false
Mouse_out_handler Assigned:false
File_dialog_start_handler Assigned:true
File_queued_handler Assigned:true
File_queue_error_handler Assigned:true
Upload_resize_start_handler Assigned:false
Upload_start_handler Assigned:true
Upload_progress_handler Assigned:true
Upload_error_handler Assigned:true
Upload_success_handler Assigned:true
Upload_complete_handler Assigned:true
Debug_handler Assigned:true
Support:
Load:yes
Image Resize:no

SWF debug:swfupload Init Complete
SWF DEBUG:
SWF Debug:-----swf Debug OUTPUT----
SWF debug:version:2.5.0 FP9 2010-02-17 Beta 3
SWF DEBUG:movieName:SWFUpload_0
SWF Debug:upload url:http://bbs.xxxx.com/misc.php?mod=swfupload&action=swfupload&operation=upload& fid=72
SWF debug:file Types String: *.jpg;*.jpeg;*.gif;*.png
SWF debug:parsed File Types:jpg,jpeg,gif,png
SWF debug:http success:0
SWF debug:file Types description:image File (*.jpg;*.jpeg;*.gif;*.png)
SWF debug:file Size limit:5120000 bytes
SWF debug:file Upload limit:0

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