DJANGOでPOST処理時に発生するMultiValueDictKeyErrorについて

勉強のため、DJANGOで簡単な仕事依頼アプリを作っている、python初心者です。
図-1の4つのclickボタンのいずれかを押してPOST処理に移行しようとすると
図-2のようにMultiValueDictKeyErrorが発生します。
ちなみに、４つのclickボタンのどれを押しても全く同じ挙動のerrorが発生します。
ソースコードの一部は下記のとおりです。恐縮ですが、errorの解決方法についてご教授いただけたら幸いです。
図-1 アプリ画面

図-2 MultiValueDictKeyError発生の様子

ソースコード
(views.py)

@login_required
def mainpage(request):

    if request.method =='POST':
        if request.POST['mode']=='__workrequest_recognition__':
            gps=workrequest.objects.filter(worker=request.user)
            workrequests=[]
            for item in gps:
                workrequests.append(item.id)
            workrequestsanswer=[]
            for item in workrequests:
                aa=request.POST['workrequest_recognitionform'+str(item)]
                workrequestsanswer.append(literal_eval(aa))
            yeslist=[]
            nolist=[]
            for item in workrequestsanswer:
                if item[0]=='yes':
                    yeslist.append(item[1])
                else:
                    nolist.append(item[1])
            yeswork=workrequest.objects.filter(id__in=yeslist)
            for item in yeswork:
                owner=item.worker
                genre=item.genre
                overview=item.overview
                priority=item.priority
                start_time=item.start_time
                end_time=item.end_time
                obj=work(owner=owner,genre=genre,overview=overview,priority=priority,start_time=start_time,end_time=end_time) 
                obj.save()
            for item in yeswork:
                requester=item.requester
                worker=item.worker
                genre=item.genre
                overview=item.overview
                priority=item.priority
                start_time=item.start_time
                end_time=item.end_time
                yesorno='の依頼は受理されました'
                objj=workrequestresponse(requester=requester,worker=worker,genre=genre,overview=overview,priority=priority,start_time=start_time,end_time=end_time,yesorno=yesorno) 
                objj.save()
            yeswork.delete()
            nowork=workrequest.objects.filter(id__in=nolist) 
            for item in nowork:
                requester=item.requester
                worker=item.worker
                genre=item.genre
                overview=item.overview
                priority=item.priority
                start_time=item.start_time
                end_time=item.end_time
                yesorno='の依頼は拒否されました'
                objj=workrequestresponse(requester=requester,worker=worker,genre=genre,overview=overview,priority=priority,start_time=start_time,end_time=end_time,yesorno=yesorno) 
                objj.save()
                nowork.delete() 
        return redirect(to='yoteihyo/')

        
    
        if request.POST['mode']=='__workrequest_responseform__':
            if request.POST['yesorno']=='yes':
                ccc=workrequestresponse.objects.filter(requester=request.user)
                ccc.delete()
        return redirect(to='yoteihyo/')



        if request.POST['mode']=='__group_request_recognition__':    
            ggg=group_request.objects.filter(groupowner=request.user)
            grouprequests=[]
            for item in ggg:
                grouprequests.append(item.id)
                grouprequestsanswer=[]
            for item in grouprequests:
                aa=request.POST['group_request_recognitionform'+str(item)]
                grouprequestsanswer.append(literal_eval(aa))
            yeslist=[]
            nolist=[]           
            for item in grouprequestsanswer:
                if item[0]=='yes':
                    yeslist.append(item[1])
                else:
                    nolist.append(item[1])
            yeswork=group_request.objects.filter(id__in=yeslist)
            for item in yeswork:
                user=item.owner
                group=item.groupname
                obj=groupmember(user=user, group=group) 
                obj.save()
                """いまここ"""
            for item in yeswork:
                owner=item.owner
                groupowner=item.groupowner
                groupid=item.groupid
                groupname=item.groupname
                yesorno='グループ入会の申請は受理されました'
                objj=group_requestresponse(owner=owner, groupowner=groupowner, groupid=groupid, groupname=groupname, yesorno=yesorno) 
                objj.save()
            yeswork.delete()
            nowork=group_request.objects.filter(id__in=nolist)
            for item in nowork:
                owner=item.owner
                groupowner=item.groupowner
                groupid=item.groupid
                groupname=item.groupname
                yesorno='グループ入会の申請は拒否されました'
                objj=group_requestresponse(owner=owner, groupowner=groupowner, groupid=groupid, groupname=groupname, yesorno=yesorno) 
                objj.save()
            nowork.delete()
        return redirect(to='yoteihyo/')
    
        if request.POST['mode']=='__grouprequest_responseform__':
            if request.POST['yesorno']=='yes':
                ccc=group_requestresponse.objects.filter(requester=request.user)
                ccc.delete()
        return redirect(to='yoteihyo/')
         
            
    else:
        
        Workrequest_recognition='2'
        schedulekari=work.objects.filter(owner=request.user)
        schedules = schedulekari.order_by('start_time') 
        time_schedule = TimeScheduleBS4(step=10, minute_height=0.5)
        time_schedule= mark_safe(time_schedule.format_schedule(schedules) )
        """仕事リクエスト処理"""
        gps=workrequest.objects.filter(worker=request.user)
        workrequests=[]
        for item in gps:
            workrequests.append(item.id)
        Workrequest_recognition=workrequest_recognition(workrequests)

        

        requestresponsecount=workrequestresponse.objects.filter(requester=request.user).count()
        if requestresponsecount>0:
            requestresponsehtml=workrequestresponse.objects.filter(requester=request.user)
            requestresponseform=workrequest_responseform()
            
        else:
            requestresponsehtml='仕事依頼に対する返信はありません'
            requestresponseform='   '   
        

        ggg=group_request.objects.filter(groupowner=request.user)
        grouprequests=[]
        for item in ggg:
            grouprequests.append(item.id)
        Grouprequest_recognition=group_request_recognition(grouprequests)
        
        grouprequestresponsecount=group_requestresponse.objects.filter(owner=request.user).count()
        if grouprequestresponsecount>0:
            grouprequestresponsehtml=group_requestresponse.objects.filter(owner=request.user)
            grouprequestresponseform=group_request_responseform()
            
        else:
            grouprequestresponsehtml='仕事依頼に対する返信はありません'
            grouprequestresponseform='   '           
    
    params={
        'getdata': Workrequest_recognition,
        'time_schedule': time_schedule,
        'requestresponsehtml':requestresponsehtml,
        'requestresponseform':requestresponseform,
        'Grouprequest_recognition':Grouprequest_recognition,
        'grouprequestresponsehtml':grouprequestresponsehtml,
        'grouprequestresponseform':grouprequestresponseform
        }    
    

    return render(request, 'schedule_app/index.html', params)

index.html

{% extends 'base.html' %}
{% block content %}
<style>
    .minute-wrapper {
        border: 1px solid #eceeef;
    }
 
    .hour-name {
        padding: 5px;
        text-align: right;
        border: 1px solid #eceeef;
    }
 
    .just-hour {
        border-top: 1px solid #eceeef;
    }
</style>
<div class="container">
    <div class="row mt-5">
        <div class="col-sm-4">
        {{ time_schedule }}
            
        </div>
        <div class="col-sm-4 bg-info text-white">
         <form action="{% url 'index' %}" method="post">
        {% csrf_token %}
        {{  getdata.as_table }}
        <tr><td></td><td><input type="submit" value="click"></td></tr>
        </form>
        </div>
       <div class="col-sm-4 bg-info text-white">
       <form action="{% url 'index' %}" method="post">
       {% csrf_token %}
       {{ Grouprequest_recognition.as_table }}
       <tr><td></td><td><input type="submit" value="click"></td></tr>
       </form>
       </div>
    </div><!-- /.row -->
    <div class="row mt-4"> 
<div class="col-sm-8 bg-info text-white">
{%for item in requestresponsehtml%}
<tr>
<td>{{item}}</td>
<tr>
{% endfor %}
</div>
<div class="col-sm-4 bg-info text-white">
<form action="{% url 'index' %}" method="post">
{% csrf_token %}
{{ requestresponseform }}
<tr><td></td><td><input type="submit" value="click"></td></tr>
</form>
</div><!-- /.row -->

<div class="row mt-4"> 
<div class="col-sm-8 bg-info text-white">
{%for item in grouprequestresponsehtml%}
<tr>
<td>{{item}}</td>
<tr>
{% endfor %}
</div>
<div class="col-sm-4 bg-info text-white">
<form action="{% url 'index' %}" method="post">
{% csrf_token %}
{{grouprequestresponseform}}
<tr><td></td><td><input type="submit" value="click"></td></tr>
</form>
</div><!-- /.row -->

    <div class="row mt-2">    
        <div class="col-sm-4">   
            <P><a href="{% url 'newwork' %}">予定の追加</a></P>
        </div>
        <div class="col-sm-4">   
            <P><a href="{% url 'newworkrequest' %}">仕事リクエスト作成</a></P>
        </div>
        <div class="col-sm-4">   
            <P><a href="{% url 'makeorapplygroup' %}">グループ作成、申請</a></P>
        </div>
    </div><!-- /.row -->
</div><!-- /.container -->
{% endblock %}