We have been trying to publish some new map services on ArcGIS for server 10.2 through using arc map basic. Previously we have had no problems publishing services however recently. We have been getting the following error:

In the server logs at the time it shows the following error messages:
| SEVERE | 16 Jun 2015 07:44:19 | Error executing tool.: ERROR 001359: Failed to connect to the server. Failed to execute (Publish Service Definition). | System/PublishingTools.GPServer |
| SEVERE | 16 Jun 2015 07:44:19 | Failed to connect to the server.: ERROR: unable to establish connection to the server. | System/PublishingTools.GPServer |
| SEVERE | 16 Jun 2015 07:44:19 | Error while using HTTPS security, URL = https://machinename:6443/arcgis/services, HTTP Status code = 0 and Status Text = (WinInet error code = 12170) | System/PublishingTools.GPServer |
| SEVERE | 16 Jun 2015 07:44:19 | Error while using HTTPS security, URL = https://machinename:6443/arcgis/services, HTTP Status code = 0 and Status Text = (WinInet error code = 12170) | System/PublishingTools.GPServer |
| SEVERE | 16 Jun 2015 07:43:22 | Error while using HTTPS security, URL = https://machinename:6443/arcgis/services, HTTP Status code = 0 and Status Text = (WinInet error code = 12170) | System/PublishingTools.GPServer |
| SEVERE | 16 Jun 2015 07:43:22 | Error while using HTTPS security, URL = https://machinename:6443/arcgis/services, HTTP Status code = 0 and Status Text = (WinInet error code = 12170) | System/PublishingTools.GPServer |
From what I can tell the ssl certificate is okay
Could any suggest any potential reasons as to why this may be happening?
Thanks
Tom