Merge Tickets NOT working after upgrade to 3.6.x

[NOORALEX]

Infos:

• Used Zammad version: Zammad version 3.6.x
• Used Zammad installation source (source, package, …): yum rpm repo (package)
• Operating system: Centos 7.9
• Browser + version: FireFox 83.0 (64-bit)

Expected behavior:

• Doing Merge for many tickets from same customer to collect all customer’s related tickets.

Actual behavior:

• When try merge ticket an error appears as shown in attached image file:

• No route matches [GET] /api/v1/ticket_merge/115948/97115872
  
  

Steps to reproduce the behavior:

[NOORALEX]

After upgrade to the latest version using the yum repository, some API URLs stopped working with 404
here is some detected from production.log

Started GET "/api/v1/tags/add?object=Ticket&o_id=116356&item=abusive+ad&_=1606161457329"

Processing by ErrorsController#routing as JSON

Parameters: {"object"=>"Ticket", "o_id"=>"116356", "item"=>"abusive ad", "_"=>"1606161457329", "a"=>"api/v1/tags/add"}

No route matches [GET] /api/v1/tags/add (ActionController::RoutingError)

Started DELETE "/api/v1/ticket_attachment_upload"

Processing by ErrorsController#routing as JSON

Parameters: {"form_id"=>"163030266", "a"=>"api/v1/ticket_attachment_upload"}

No route matches [DELETE] /api/v1/ticket_attachment_upload (ActionController::RoutingError)

Started GET "/api/v1/ticket_related/116356?_=1606161457335"

Processing by TicketsController#ticket_related as JSON

Parameters: {"_"=>"1606161457335", "ticket_id"=>"116356"}

Completed 200 OK in 178ms (Views: 28.9ms | ActiveRecord: 32.4ms)

Started GET "/api/v1/ticket_merge/116356/97116278?_=1606161457336"

Processing by ErrorsController#routing as JSON

Parameters: {"_"=>"1606161457336", "a"=>"api/v1/ticket_merge/116356/97116278"}

No route matches [GET] /api/v1/ticket_merge/116356/97116278 (ActionController::RoutingError)

while zammad run rake routes result for those three methods:
PUT /api/v1/ticket_merge/:slave_ticket_id/:master_ticket_number(.:format)
POST /api/v1/tags/add(.:format)

Please note browser cache is deleted and also tested on other browsers

Thank you in advance

[MrGeneration]

We have several threads with this topic.
Ensure the browser cache is cleared and the update was really completed and successful.

Clearing Zammads own cache with restarting may help too:
systemctl stop zammad; zammad run rails r "Cache.clear"; systemctl start zammad