Issues with customize form on 14.0.0-beta3

Migrated from 13.5 to 14.0.0-beta3, including moving old customised forms. Things seem to be going fine except that I get the error below when going to customise the form for any document type. Customising the doctype itself works fine. This shows Buying > Request for Quotation as an example:

  1. XHR POSThttps://hr.mimirtech.com/api/method/run_doc_method
    [HTTP/1.1 500 Internal Server Error 91ms]

Unable to handle failed response

  1. console.trace() SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data
    report_error request.js:491
    500 request.js:202
    call request.js:328
    jQuery 6
    call request.js:253
    call request.js:103
    call form.js:1568
    doc_type customize_form__js:77
    p script_manager.js:30
    s script_manager.js:108
    trigger script_manager.js:126
    promise callbackfrappe.run_serially/< dom.js:265
    run_serially dom.js:263
    trigger script_manager.js:140
    watch_model_updates form.js:264
    a model.js:480
    promise callback
    frappe.run_serially/< dom.js:265
    run_serially dom.js:263
    trigger model.js:498
    set_value model.js:441
    promise callbackfrappe.run_serially/< dom.js:265
    run_serially dom.js:263
    set_value model.js:450
    s form.js:1498
    set_value form.js:1508
    set_default_doc_type customize_form__js:177
    setTimeout handler
    set_default_doc_type customize_form__js:177
    p script_manager.js:30
    refresh customize_form__js:163
    p script_manager.js:30
    s script_manager.js:108
    trigger script_manager.js:126
    promise callbackfrappe.run_serially/< dom.js:265
    run_serially dom.js:263
    trigger script_manager.js:140
    render_form form.js:551
    promise callback
    frappe.run_serially/< dom.js:265
    request.js:335:12
    call request.js:335
    jQuery 6
    call request.js:253
    call request.js:103
    call form.js:1568
    doc_type customize_form__js:77
    p script_manager.js:30
    s script_manager.js:108
    trigger script_manager.js:126
    (Async: promise callback)
    run_serially dom.js:265
    run_serially dom.js:263
    trigger script_manager.js:140
    watch_model_updates form.js:264
    a model.js:480
    (Async: promise callback)
    run_serially dom.js:265
    run_serially dom.js:263
    trigger model.js:498
    set_value model.js:441
    (Async: promise callback)
    run_serially dom.js:265
    run_serially dom.js:263
    set_value model.js:450
    s form.js:1498
    set_value form.js:1508
    set_default_doc_type customize_form__js:177
    (Async: setTimeout handler)
    set_default_doc_type customize_form__js:177
    p script_manager.js:30
    refresh customize_form__js:163
    p script_manager.js:30
    s script_manager.js:108
    trigger script_manager.js:126
    (Async: promise callback)
    run_serially dom.js:265
    run_serially dom.js:263
    trigger script_manager.js:140
    render_form form.js:551
    (Async: promise callback)
    run_serially dom.js:265

  2. Uncollapsing the XHR request in the first point shows the request data as:

docs “{“name”:“Customize+Form”,“owner”:“Administrator”,“docstatus”:0,“idx”:0,“max_attachments”:0,“allow_copy”:0,“istable”:0,“editable_grid”:0,“quick_entry”:1,“track_changes”:0,“track_views”:0,“allow_auto_repeat”:0,“allow_import”:0,“show_title_field_in_link”:0,“show_preview_popup”:0,“email_append_to”:0,“sort_order”:“ASC”,“doctype”:“Customize+Form”,“fields”:[],“actions”:[],“links”:[],“states”:[],”__last_sync_on":“2022-04-29T05:27:22.683Z”,“doc_type”:“Request+for+Quotation”}"
method “fetch_to_customize”

and the response is a 500 Internal Server Eroor.

I do not see anything wrong in the JSON

We also reported an issue related to customize form that is in the milestone for v14 release v14.0 Milestone · GitHub

Great. Thanks for the pointer. I did search the Github repository, but somehow seem to have missd this.