AttributeError: 'NoneType' object has no attribute 'default'

Frappe Framework Print Formats
1

Hi all
I am getting an error whenever I try to open the print format on most of the doc_types where I have made my custom printformats. These formats were running fine in earlier versions but had started showing the above server error after migrating to v13. If I close the error dialog the print format is displayed correctly. This is the complete error.

{{

App Versions

{
	"erpnext": "13.20.1",
	"frappe": "13.20.1"
}

Route

print/Delivery Note/DN-01876

Trackeback

Traceback (most recent call last):
  File "apps/frappe/frappe/app.py", line 68, in application
    response = frappe.api.handle()
  File "apps/frappe/frappe/api.py", line 55, in handle
    return frappe.handler.handle()
  File "apps/frappe/frappe/handler.py", line 31, in handle
    data = execute_cmd(cmd)
  File "apps/frappe/frappe/handler.py", line 68, in execute_cmd
    return frappe.call(method, **frappe.form_dict)
  File "apps/frappe/frappe/__init__.py", line 1214, in call
    return fn(*args, **newargs)
  File "apps/frappe/frappe/printing/page/print/print.py", line 16, in get_print_settings_to_show
    df.default = print_settings.get(fieldname)
AttributeError: 'NoneType' object has no attribute 'default'

Request Data

{
	"type": "POST",
	"args": {
		"doctype": "Delivery Note",
		"docname": "DN-01876"
	},
	"headers": {},
	"error_handlers": {},
	"url": "/api/method/frappe.printing.page.print.print.get_print_settings_to_show"
}

Response Data

{
	"exception": "AttributeError: 'NoneType' object has no attribute 'default'"
}

}}

Any pointers would be helpful to debug.
Thanks

2

@arpanzen your table Print settings is missing some attributes . did you moved your data from 12 to 13 via a backup and restore ?

3

Thanks for your reply.
I transferred data from V12 production server to V12 to a cloud server, via backup and restore and then migrated the cloud server to V13.

I have tried to copy the HTML print format and pasted it by new name but it still doesnt work. Could it be related to VUE. I am still getting errors on bench update

UNRESOLVED_IMPORT : 'vue/dist/vue.js'
4

@arpanzen the problem is that the database was rebuilt using your data from v12 . some fields are not the same , so the app will throw errors when it can’t find some fields that suppose to be in v13 . have you tried a bench build and migrate ?

5

Yes I have already tried build and migrate. If i delete existing print formats and make new ones from the existing html code then also i am getting same error.

6

@arpanzen is it happening to all doctypes to print or only the the one you are trying to print ?

7

It is happening to most of the doctypes but one or two are still working fine and when i close the dialog after this error the data is displayed correctly on the printformat. So it is some hidden setting that is causing the issue.

8

@arpanzen try this . open print settings folder from terminal (apps/frappe/frappe/printing/doctype/print_setting) and then open print_setting.json and search for modified . change the time to a recent one like this morning . save the file and run a bench migrate . that will force the table to rebuild . I hope it’s the table that is missing some field otherwise it will be all the other doctypes .

9

I did as you had suggested, and then bench migrate and bench build. Everything went well, no errors except UNRESOLVED_IMPORT : ‘vue/dist/vue.js’

When all done. Tried the print formats but it still throws same error.

10

@arpanzen a temporary solution : open the file apps/frappe/frappe/printing/page/print/print.py and comment the line that makes error or put it in a try except . it’s not very important . I tried it

11

Thanks, the workaround removed the error. Hope it does not affect anything.
Thanks again for your help. Do let me know if you could suggest something later for a permanent fix. I have been migrating our companies data from V5 till now and would not like to do away with it.

12

@arpanzen don’t worry about the code . it’s for getting some default settings , the print will just work fine without them . for a permanent solution you need to know where exactly the df variable come from . its table is missing something and needs to be rebuilt.