ArcGIS server connection issue from my laptop and desktop

[YeshiWangchuk]

Hi,

I am Yeshi and we have been using ESRI ArcGIS 10.3 for the past 7 years that we have procured form ESRI. recently we have been facing some issues with it. when we try to open ArcMap form our laptop and desktop. we are not able to open it as it is throwing us some issue. 

PFA the error image below.

Looking forward for your kind support

[JayantaPoddar]

Error: Provide your license server administrator with the following information: Error Code = -15 (e...

1. Ensure ArcGIS License Administrator is running, and its version should be same or higher than ArcMap version.

2. Defining a dedicated port for the ArcGIS License Manager could be a good idea (please refer the above link).