c# - Microsoft.Office.Interop.Word.Document won't prompt to save changes to single document without _Application.Quit() -

before begin, have googled death , there many posts how prevent save prompt. having issue showing save prompt.

i building template editing portion of document generation system in c#. system edit 'dot' , 'dotx' files. before outlining problem, environment using development running visual studio 2010 , word 2010. run on other versions, these versions functional first.

to set scene have form open has list of columns returned stored procedure(data source) add document bookmarks. have of bookmark , drag/drop operations functional. when close application, catch 'applicationevents4_documentbeforecloseeventhandler' event close form.

when close form, check haw many documents there open. if 1 document open, close application prompts user save changes. if there multiple documents open (most people have number of different word documents open concurrently), locate correct document , close flag set prompt user save changes.

this problem occurs. @ point, save changes dialog never shows , freezes in visual studio. if stop debugging on visual studio 2010 document flashes in task bar indefinitely, , if focus on it, disappears , saves changes without prompt.

this code handle form closing event:

private void form2_formclosing(object sender, formclosingeventargs e)     {         if (app != null)         {             if (app.documents.count < 2)             {                 this.topmost = false;                 ((word._application)app).quit();                 app = null;             }             else             {                 foreach (word.document document in app.documents)                 {                     if (document.fullname.equals(worddoc.fullname))                     {                         object savechanges = word.wdsaveoptions.wdprompttosavechanges;                         ((word._document)worddoc).close(ref savechanges);                         break;                     }                 }             }         }     } 

the problem line should show save changes dialog:

((word._document)worddoc).close(ref savechanges); 

i have tried debugging without luck. putting breakpoint on line , on

break; 

line allows program stop @ 'close' line when 'step' forward or 'continue' word becomes unresponsive, form , breakpoint on next line never gets hit.

any appreciated simple annoying stuck on.

to avoid prompt or prompt have set saved property true or false respectively:

var doco = wordapp.documents.add(); doco.saved = true; doco.close(microsoft.office.interop.word.wdsaveoptions.wddonotsavechanges, type.missing, type.missing); 

something fishy going on if word hangs on line of code when try close document. recommend disposing of resources properly. here great article on using vsto contrib helps provide functionality:

http://jake.ginnivan.net/vsto-com-interop

update:

enable vsto log file adding following on system environment variables:

name: vsto_logalerts value: 1 there might exception error why add-in not loading.

you can check source more info on vsto logging , alerts, in essence change 2 environment variable values depending on need do:

displaying vsto alert prompts

to display each error in message box, set vsto_suppressdisplayalerts variable 0 (zero). can suppress messages setting variable 1 (one).

logging vsto alerts log file

to write errors log file, set vsto_logalerts variable 1 (one).

visual studio tools office creates log file in folder contains application manifest. default name .manifest.log. stop logging errors, set variable 0 (zero).