Blank admin screen after admin login

[Robert Rood]

Hello...after logging in to the admin page all I get is a blank white screen. The error log shows as follows:

AbanteCart core v.1.2.15 Class 'Modelsalecustomer' not found in <b>/home1/***/public_html/cart/core/engine/loader.php</b> on line <b>114</b>

Can someone please help?!?!

Thank you,
Robert Rood

[Basara]

Hello.
Did you install recently any extensions or modify AbanteCart code?