Errors when saving listings

Hello!

We have changed our categories to multi-categories.
Since then we have been getting a lot of weird issues and errors when we try to save our listings.

When we use the "Save as Copy" function to copy a whole set of a specific user's listings. We are getting this error:

Notice: Undefined index: listPageOrder in C:\Domains\rentittoday.com\wwwroot\cmsAdmin\lib\viewer_functions.php on line 67

When we try to save a listing, Real Estate for example, we get this error:
Notice: Undefined index: what_colleges in C:\Domains\rentittoday.com\wwwroot\cmsAdmin\lib\menus\default\save.php on line 336 Notice: Undefined index: school_district in C:\Domains\rentittoday.com\wwwroot\cmsAdmin\lib\menus\default\save.php on line 336 Notice: Undefined index: rent in C:\Domains\rentittoday.com\wwwroot\cmsAdmin\lib\menus\default\save.php on line 336 Notice: Undefined index: deposit_amount in C:\Domains\rentittoday.com\wwwroot\cmsAdmin\lib\menus\default\save.php on line 336 Notice: Undefined index: purchase_amount in C:\Domains\rentittoday.com\wwwroot\cmsAdmin\lib\menus\default\save.php on line 336 Notice: Undefined index: pay_commission in C:\Domains\rentittoday.com\wwwroot\cmsAdmin\lib\menus\default\save.php on line 336 Notice: Undefined index: how_much in C:\Domains\rentittoday.com\wwwroot\cmsAdmin\lib\menus\default\save.php on line 336 Notice: Undefined index: requirement_expectations in C:\Domains\rentittoday.com\wwwroot\cmsAdmin\lib\menus\default\save.php on line 340 'Rent' is required! 'Deposit Amount' is required!

Sometimes is seems to save "ok" despite the error and other times it will not work at all.

Any ideas as to what is going on?
Thanks!