Ignition 8.3 system.util.sendRequest() causes an exception

[atsm26]

I am trying to do a basic message event between two gateways and I am getting an exception from the system.util.sendRequest() function

payload = {
	"program": program,
	"machine_id": machine_id
}
response = system.util.sendRequest(
	project = "ProjectName",
	messageHandler = "RequestProgram",
	remoteServer = "GatewayName",
	payload = payload,
	timeoutSec = 120
)
return response

The handler that I am trying to send to literally just has “return True”

I am also trying to send the request from the gateway itself as shown below and it doesn’t work

payload = {
	"program": program,
	"machine_id": machine_id
}
response = system.util.sendRequest(
	project = system.util.getProjectName(),
	messageHandler = "RequestProgram",
	remoteServer = system.tag.readBlocking("[System]Gateway/SystemName")[0].value,
	payload = payload,
	timeoutSec = 120
)
return response

The shortened error I am getting is down below:

Traceback (most recent call last):
  File "<input>", line 5, in <module>
	at java.base/java.util.concurrent.CompletableFuture.reportGet(Unknown Source)

	at java.base/java.util.concurrent.CompletableFuture.get(Unknown Source)

	at com.inductiveautomation.ignition.common.script.builtin.SystemUtilities.sendRequest(SystemUtilities.java:827)

	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

	at java.base/java.lang.reflect.Method.invoke(Unknown Source)

java.util.concurrent.ExecutionException: java.util.concurrent.ExecutionException: java.lang.ClassCastException: class java.util.Collections$UnmodifiableMap cannot be cast to class org.python.core.PyDictionary (java.util.Collections$UnmodifiableMap is in module java.base of loader 'bootstrap'; org.python.core.PyDictionary is in unnamed module of loader 'app')

This worked before we upgraded to 8.3 but doesn’t now. Any ideas why?

[Kevin.Herron]

This just got reported in another thread this morning, it's being looked into.

[paul-griffith]

If you freshly launch the designer, does this problem still occur?
If so, is there an error at the beginning of your designer's logging output with a message Failed to retrieve script message encoding, defaulting to JSON? If so, can you post the full related stacktrace here?

[atsm26]

I tried it again this morning. I dont see “Failed to retrieve script message encoding, defaulting to JSON” anywhere. Stack and my console log shown below:

Java Traceback: Traceback (most recent call last):   File "<input>", line 5, in <module> 	at java.base/java.util.concurrent.CompletableFuture.reportGet(Unknown Source)  	at java.base/java.util.concurrent.CompletableFuture.get(Unknown Source)  	at com.inductiveautomation.ignition.common.script.builtin.SystemUtilities.sendRequest(SystemUtilities.java:827)  	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)  	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)  	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)  	at java.base/java.lang.reflect.Method.invoke(Unknown Source)  java.util.concurrent.ExecutionException: java.util.concurrent.ExecutionException: java.lang.ClassCastException: class java.util.Collections$UnmodifiableMap cannot be cast to class org.python.core.PyDictionary (java.util.Collections$UnmodifiableMap is in module java.base of loader 'bootstrap'; org.python.core.PyDictionary is in unnamed module of loader 'app')   	at org.python.core.Py.JavaError(Py.java:545)  	at org.python.core.Py.JavaError(Py.java:536)  	at org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:192)  	at com.inductiveautomation.ignition.common.script.ScriptManager$ReflectedInstanceFunction.__call__(ScriptManager.java:563)  	at org.python.core.PyObject.__call__(PyObject.java:400)  	at org.python.pycode._pyx9.f$0(<input>:12)  	at org.python.pycode._pyx9.call_function(<input>)  	at org.python.core.PyTableCode.call(PyTableCode.java:173)  	at org.python.core.PyCode.call(PyCode.java:18)  	at org.python.core.Py.runCode(Py.java:1703)  	at org.python.core.Py.exec(Py.java:1747)  	at org.python.util.PythonInterpreter.exec(PythonInterpreter.java:277)  	at org.python.util.InteractiveInterpreter.runcode(InteractiveInterpreter.java:130)  	at com.inductiveautomation.ignition.designer.gui.tools.jythonconsole.JythonConsole$ConsoleWorker.doInBackground(JythonConsole.java:628)  	at com.inductiveautomation.ignition.designer.gui.tools.jythonconsole.JythonConsole$ConsoleWorker.doInBackground(JythonConsole.java:616)  	at java.desktop/javax.swing.SwingWorker$1.call(Unknown Source)  	at java.base/java.util.concurrent.FutureTask.run(Unknown Source)  	at java.desktop/javax.swing.SwingWorker.run(Unknown Source)  	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)  	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)  	at java.base/java.lang.Thread.run(Unknown Source)  Caused by: java.util.concurrent.ExecutionException: java.lang.ClassCastException: class java.util.Collections$UnmodifiableMap cannot be cast to class org.python.core.PyDictionary (java.util.Collections$UnmodifiableMap is in module java.base of loader 'bootstrap'; org.python.core.PyDictionary is in unnamed module of loader 'app')  	at java.base/java.util.concurrent.CompletableFuture.reportGet(Unknown Source)  	at java.base/java.util.concurrent.CompletableFuture.get(Unknown Source)  	at com.inductiveautomation.ignition.common.script.builtin.SystemUtilities.sendRequest(SystemUtilities.java:827)  	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)  	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)  	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)  	at java.base/java.lang.reflect.Method.invoke(Unknown Source)  	at org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:190)  	... 18 more  Caused by: java.lang.ClassCastException: class java.util.Collections$UnmodifiableMap cannot be cast to class org.python.core.PyDictionary (java.util.Collections$UnmodifiableMap is in module java.base of loader 'bootstrap'; org.python.core.PyDictionary is in unnamed module of loader 'app')  	at com.inductiveautomation.ignition.gateway.script.rpc.ScriptMessagingRpcImpl.extractPayload(ScriptMessagingRpcImpl.java:93)  	at com.inductiveautomation.ignition.gateway.script.rpc.ScriptMessagingRpcImpl.dispatchRequest(ScriptMessagingRpcImpl.java:69)  	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(:0)  	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(:0)  	at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(:0)  	at java.lang.reflect.Method.invoke(:0)  	at com.inductiveautomation.ignition.gateway.rpc.RpcDelegate$DelegateRpcHandler.handle(RpcDelegate.java:271)  	at com.inductiveautomation.ignition.gateway.rpc.RpcRoutes.lambda$handle$1(RpcRoutes.java:199)  	at com.inductiveautomation.ignition.gateway.rpc.RpcRoutes.safelyHandle(RpcRoutes.java:219)  	at com.inductiveautomation.ignition.gateway.rpc.RpcRoutes.handle(RpcRoutes.java:198)  	at com.inductiveautomation.ignition.gateway.dataroutes.Route.service(Route.java:361)  	at com.inductiveautomation.ignition.gateway.dataroutes.RouteGroupImpl.service(RouteGroupImpl.java:120)  	at com.inductiveautomation.ignition.gateway.dataroutes.RouteGroupCollectionServlet.serviceInternal(RouteGroupCollectionServlet.java:133)  	at com.inductiveautomation.ignition.gateway.dataroutes.AbstractRouteGroupServlet.service(AbstractRouteGroupServlet.java:40)  	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:614)  	at org.eclipse.jetty.ee10.servlet.ServletHolder$NotAsync.service(ServletHolder.java:1379)  	at org.eclipse.jetty.ee10.servlet.ServletHolder.handle(ServletHolder.java:736)  	at org.eclipse.jetty.ee10.servlet.ServletHandler$ChainEnd.doFilter(ServletHandler.java:1614)  	at com.inductiveautomation.catapult.filters.GatewayFilter.doFilter(GatewayFilter.java:116)  	at jakarta.servlet.http.HttpFilter.doFilter(HttpFilter.java:97)  	at org.eclipse.jetty.ee10.servlet.FilterHolder.doFilter(FilterHolder.java:208)  	at org.eclipse.jetty.ee10.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1586)  	at org.eclipse.jetty.ee10.servlet.ServletHandler$MappedServlet.handle(ServletHandler.java:1547)  	at org.eclipse.jetty.ee10.servlet.ServletChannel.dispatch(ServletChannel.java:819)  	at org.eclipse.jetty.ee10.servlet.ServletChannel.handle(ServletChannel.java:436)  	at org.eclipse.jetty.ee10.servlet.ServletHandler.handle(ServletHandler.java:464)  	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:575)  	at org.eclipse.jetty.ee10.servlet.SessionHandler.handle(SessionHandler.java:717)  	at org.eclipse.jetty.server.handler.ContextHandler.handle(ContextHandler.java:1060)  	at org.eclipse.jetty.rewrite.handler.RewriteHandler$LastRuleHandler.handle(RewriteHandler.java:159)  	at org.eclipse.jetty.rewrite.handler.Rule$Handler.handle(Rule.java:108)  	at org.eclipse.jetty.rewrite.handler.HeaderPatternRule$1.handle(HeaderPatternRule.java:89)  	at org.eclipse.jetty.rewrite.handler.Rule$Handler.handle(Rule.java:108)  	at org.eclipse.jetty.rewrite.handler.HeaderPatternRule$1.handle(HeaderPatternRule.java:89)  	at org.eclipse.jetty.rewrite.handler.Rule$Handler.handle(Rule.java:108)  	at org.eclipse.jetty.rewrite.handler.HeaderPatternRule$1.handle(HeaderPatternRule.java:89)  	at org.eclipse.jetty.rewrite.handler.Rule$Handler.handle(Rule.java:108)  	at org.eclipse.jetty.rewrite.handler.HeaderPatternRule$1.handle(HeaderPatternRule.java:89)  	at org.eclipse.jetty.rewrite.handler.Rule$Handler.handle(Rule.java:108)  	at org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:143)  	at org.eclipse.jetty.server.Handler$Sequence.handle(Handler.java:805)  	at org.eclipse.jetty.server.Handler$Sequence.handle(Handler.java:805)  	at org.eclipse.jetty.server.Server.handle(Server.java:182)  	at org.eclipse.jetty.server.internal.HttpChannelState$HandlerInvoker.run(HttpChannelState.java:662)  	at org.eclipse.jetty.server.internal.HttpConnection.onFillable(HttpConnection.java:418)  	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:322)  	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:99)  	at org.eclipse.jetty.io.ssl.SslConnection$SslEndPoint.onFillable(SslConnection.java:575)  	at org.eclipse.jetty.io.ssl.SslConnection.onFillable(SslConnection.java:390)  	at org.eclipse.jetty.io.ssl.SslConnection$2.succeeded(SslConnection.java:150)  	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:99)  	at org.eclipse.jetty.io.SelectableChannelEndPoint$1.run(SelectableChannelEndPoint.java:53)  	at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.runTask(AdaptiveExecutionStrategy.java:478)  	at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.consumeTask(AdaptiveExecutionStrategy.java:441)  	at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.tryProduce(AdaptiveExecutionStrategy.java:293)  	at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.run(AdaptiveExecutionStrategy.java:201)  	at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:311)  	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:979)  	at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.doRunJob(QueuedThreadPool.java:1209)  	at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1164)  	at java.lang.Thread.run(:0)  Traceback (most recent call last):   File "<input>", line 5, in <module> 	at java.base/java.util.concurrent.CompletableFuture.reportGet(Unknown Source)  	at java.base/java.util.concurrent.CompletableFuture.get(Unknown Source)  	at com.inductiveautomation.ignition.common.script.builtin.SystemUtilities.sendRequest(SystemUtilities.java:827)  	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)  	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)  	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)  	at java.base/java.lang.reflect.Method.invoke(Unknown Source)  java.util.concurrent.ExecutionException: java.util.concurrent.ExecutionException: java.lang.ClassCastException: class java.util.Collections$UnmodifiableMap cannot be cast to class org.python.core.PyDictionary (java.util.Collections$UnmodifiableMap is in module java.base of loader 'bootstrap'; org.python.core.PyDictionary is in unnamed module of loader 'app')

This is what I ran directly.

payload = {
	"program": "program",
	"machine_id": "machine_id"
}
response = system.util.sendRequest(
	project = "ProjectName",
	messageHandler = "RequestProgram",
	remoteServer = "GatewayName",
	payload = payload,
	timeoutSec = 120
)
print response

[paul-griffith]

Echoing my response from this other thread for visibility - and thank you @atsm26 also for your report.

sendRequest not possible in script console

Thanks, I was able to figure out the root cause and work out a fix. Hopefully will get in to 8.3.1, if not 8.3.2. If you restart the gateway and the designer, it should work consistently until/unless you change the 'Script Message Encoding' property in the gateway settings.

[atsm26]

Thanks for the response and working on it! Appreciate it