I am facing the same issue,
But restarting the "AEM Forms Dermis Core" didn't work for me.
Is there something I might be missing?
here are the steps followed :
AEM version : 6.5
AEM forms package :
adobe-aemfd-win-pkg-6.0.80.zip
jdbc-driver osgi bundle is installed.
MYSQL is used for datasource .
when I try to create a data model using the datasource mentioned in the configuration.
still I get thie following error when the data model loads
12.06.2019 18:21:13.405 *ERROR* [0:0:0:0:0:0:0:1 [1560343873402] POST /libs/fd/fdm/content/crud.dermis.formDataModelManager.json HTTP/1.1] com.adobe.aem.dermis.exception.DermisException Unable to retrieve Data Context for configuration Ultratech
12.06.2019 18:21:13.407 *WARN* [0:0:0:0:0:0:0:1 [1560343873402] POST /libs/fd/fdm/content/crud.dermis.formDataModelManager.json HTTP/1.1] com.googlecode.jsonrpc4j.JsonRpcServer Error in JSON-RPC Service
java.lang.reflect.InvocationTargetException: null
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.googlecode.jsonrpc4j.JsonRpcServer.invoke(JsonRpcServer.java:513) [jsonrpc-bundle:1.0.8]
at com.googlecode.jsonrpc4j.JsonRpcServer.handleObject(JsonRpcServer.java:384) [jsonrpc-bundle:1.0.8]
at com.googlecode.jsonrpc4j.JsonRpcServer.handleNode(JsonRpcServer.java:293) [jsonrpc-bundle:1.0.8]
at com.googlecode.jsonrpc4j.JsonRpcServer.handle(JsonRpcServer.java:230) [jsonrpc-bundle:1.0.8]
at com.googlecode.jsonrpc4j.JsonRpcServer.handle(JsonRpcServer.java:207) [jsonrpc-bundle:1.0.8]
at com.adobe.livecycle.remoting.internal.JsonInvokerServlet.invokeService(JsonInvokerServlet .java:166) [com.adobe.livecycle.remoting:6.0.26]
at com.adobe.livecycle.remoting.internal.RemotingBaseServlet.doPost(RemotingBaseServlet.java :101) [com.adobe.livecycle.remoting:6.0.26]
at org.apache.sling.api.servlets.SlingAllMethodsServlet.mayService(SlingAllMethodsServlet.ja va:146) [org.apache.sling.api:2.18.4]
at org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMethodsServlet.jav a:342) [org.apache.sling.api:2.18.4]
at org.apache.sling.api.servlets.SlingSafeMethodsServlet.service(SlingSafeMethodsServlet.jav a:374) [org.apache.sling.api:2.18.4]
at org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:552) [org.apache.sling.engine:2.6.18]
at org.apache.sling.engine.impl.filter.SlingComponentFilterChain.render(SlingComponentFilter Chain.java:44) [org.apache.sling.engine:2.6.18]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilter Chain.java:82) [org.apache.sling.engine:2.6.18]
at com.day.cq.wcm.core.impl.WCMDebugFilter.doFilter(WCMDebugFilter.java:156) [com.day.cq.wcm.cq-wcm-core:5.12.90]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilter Chain.java:72) [org.apache.sling.engine:2.6.18]
at com.day.cq.wcm.core.impl.WCMComponentFilter.filterRootInclude(WCMComponentFilter.java:375 ) [com.day.cq.wcm.cq-wcm-core:5.12.90]