i'am working with multi company , everything was going well, but suddenly users of one company can't access point of sale module and if he press the point of sale menu ge get the error 
​      The requested operation cannot be completed due to security restrictions. Please contact your system administrator.​

i'am also tried to access the point of sale with adminstrator user with this company i get the same error 

The requested operation cannot be completed due to security restrictions. Please contact your system administrator.

(Document type: Users, Operation: read) - (Records: [12], User: 2) 

how can i solve this issue that happens suddenly, whithout any change in anything

`