HTTP Code 503

Hi

I've started getting this error the last week or so - http error 503 when I click on Process activity, or indeed any of the other tabs in the image. Happens the first time I click, but not the second.

What could be going on here? Browser issue? Network latency? It also happens in on of our applications in a record type sort - again the first time the user clicks on the column heading.

Using chrome, 93.0.4577.63. Can make the error go away by cleaning out the cache, but this could be just coincidental?

Seeing this in the tomcat log at around the same time, this is the first few lines.

Any ideas?

2021-09-21 07:02:09,555 [ajp-nio-0.0.0.0-8009-exec-1619] ERROR com.appiancorp.rest.shared.FallbackExceptionMapper - Internal Server Error on REST API invocation.
org.apache.catalina.connector.ClientAbortException: java.io.EOFException
	at org.apache.catalina.connector.InputBuffer.realReadBytes(InputBuffer.java:330)
	at org.apache.catalina.connector.InputBuffer.checkByteBufferEof(InputBuffer.java:630)
	at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:348)
	at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:183)
	at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
	at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
	at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
	at java.io.InputStreamReader.read(InputStreamReader.java:184)
	at java.io.Reader.read(Reader.java:140)