My admin panel is not working

[sabet]

after upgrading abantecart to 1.2.12 my admin panel is not working though it uploads , but when I click on products to edit prices or clicking on category I got redirected to my home page ?
plz help me .

[eCommerce Core]

Did you get an error during upgrade? If upgrade did not complete with error, you need to take a note of this error. You can find it in the error log.

If this is the case, restore your site with the backup first.

Share the error you get and we will see what the issue is. 

[sabet]

unfortunately I didn't make a back up before upgrading and I didn't get any error messages .

[Basara]

unfortunately I didn't make a back up before upgrading and I didn't get any error messages .

Check the error log file

[eCommerce Core]

Check your backup directory. Upgrade process (if you did it within the browser) creates a backup first.

[sabet]

that is the error messages .
2018-06-01 5:26:57 - App Warning: AbanteCart core v.1.2.12 ADispatch: blocks/custom_form_block construct FAILED. Missing or incorrect controller route path. Possibly, layout block is enabled for disabled or missing extension! Execution stack: - /home/xxxxxx195/public_html/core/engine/dispatcher.php(76): genExecTrace('full')

[Basara]

This is not important warning not related to upgrade

[eCommerce Core]

that is the error messages .
2018-06-01 5:26:57 - App Warning: AbanteCart core v.1.2.12 ADispatch: blocks/custom_form_block construct FAILED. Missing or incorrect controller route path. Possibly, layout block is enabled for disabled or missing extension! Execution stack: - /home/xxxxxx195/public_html/core/engine/dispatcher.php(76): genExecTrace('full')

Execution stack would be helpful to see.
Do you have any third party extensions? Try to disable them one by one?

[sabet]

what do you mean by Execution stack would be helpful to see. ?
I don,t have a third party extension .