Recently, we have run into "Unable to load workflow actions from the server" multiple times when users try to create or modify a workflow using SharePoint designer. Here is the error message.
It seems worth to summarize the major possible reason that might cause the issue and the procedure to fix it.
First, missing feature is the most common reason. You could follow blog to use Fiddler verifying any missing feature. We had removed Bamboo PM suit from our environment but some reference still remained on app server. The Fiddler captures the missing feature error as in the following screenshot. The action is to clean up the feature or add back the feature if needed.’s
You can identify the exactly missing feature is as highlighted. The solution is to clean up the Bamboo features and components in our case. If you still need the missing feature, you should install again to avoid such issue.
<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><soap:Fault><faultcode>soap:Server</faultcode><faultstring>Exception of type 'Microsoft.SharePoint.SoapServer.SoapServerException' was thrown.</faultstring><detail><errorstring xmlns="http://schemas.microsoft.com/sharepoint/soap/">Failed to find the XML file at location '14\Template\Features\ProjectCentralContentTypes\feature.xml'</errorstring><errorcode xmlns="http://schemas.microsoft.com/sharepoint/soap/">0x80131600</errorcode></detail></soap:Fault></soap:Body></soap:Envelope>
Second, corrupted workflow action file is the second common reason. You could verify the procedure form Microsoft site. The action is to copy the correct workflow action file and bounce IIS. We had corrupted file on one of the WFEs and it was fixed by coping the file from another server.
Third, corrupted SharePoint designer cache. You can delete the designer cache as described in this blog.
There may be some other reasons that might cause the same issue. You should always try to IISRESET and clean up designer cache as the first two steps.