call_user_func_array () expects parameter 1 to be a valid callback, no array or

Hello,

I use the plugin for about a year. Until a few weeks ago, it worked perfectly. Meanwhile every time I add a new page I get the following error.

call_user_func_array () expects parameter 1 to be a valid callback, no array or string given in /homepages/0/d680925801/htdocs/clickandbuilds/WordPress/MyCMS2/wp-content/plugins/if-menu/if-menu.php on line 99

In recent times, it was enough if I disabled the plugin and reactivated. Today I have the problem continually. Disabling and reactivating is not enough. Slowly it is annoying. What is this problem?

So I can not continue working with this really good plugin. It would be nice if you make sure that this error is corrected permanently.

Just for information: I have had no updates for my theme or something similar, which has caused similar problems with other users in the past. The error always only occurs when I add a new page on my website.

Unfortunately I’m thinking about replacing the plugin with another one – unfortunately. Can someone help me and make sure that this problem is finally resolved?

Thanks in advance!