backend fails after joomla 3.4.4 update

hello

after install the update of joomla 3.4.4 or the akeeba update...the backend doesn't works well

happends that in isis (or other template) backend..in MENUS I can't save / cancel / save and new /...and doesn't appear the menu options.

How I can fix this error on menus?

thank you

HI,
this is quite popular Joomla issue. In most cases you have to clear your browser cache, if won't help check on official joomla forum.

do you have any link?

bc I searched on google and I can't find any solution..on other templates it doesn´t happend

i only find that..and they haven't solutions

https://github.com/joomla/joomla-cms/issues/7374

Try to reload template, I mean reinstall with new current version

and all the changes we had made on the template? we're gonna lose it?

First make a template copy, and after update - replace again only those files which you changed already.
I guess you made changes in 1-2-3 files only, hmm.
Using new template version always fix old problems. BTW you can also read changelog https://www.gavick.com/updates
to check which files has been upgraded.