Troubleshooting
Problem
The Modeler
Symptom
"Unexpected end of ZLIB input stream"
Cause
The error message means that the stream file is invalid. The compression procedure involved in creating a stream file is performed by the Java Virtual Machine that is responsible for handling the User Interface. If Modeler Client is closed before the stream has finished saving, then the resulting stream file will be incomplete. To date this problem has been reported only on a few occasions and the lack of available information into the environment leading up to this problem means the problem has not been replicated. If you see Modeler client using a lot of RAM (that the two numbers in the bottom right-hand-corner of the Modeler workpane are very close to each other), then it is possible that saving a large stream within that session will take a significant amount of time as the JVM is using as much memory as it is currently allowed to. In this situation please allow the stream save process to complete - the presence of the hourglass cursor within Modeler client for an extended time in this situation does not indicate an application hang and therefore does not indicate in itself the need for a forceful termination of the process.
We are investigating if we can make it clearer to the user that the stream save is still in progress.
Note it is possible for external factors to corrupt Modeler streams just as they can corrupt any files. If you have Modeler streams that suddenly appear corrupt, but Modeler hasn't been used to load or save them since previously successful use, then it is likely that something external has corrupted the files on your filesystem. If this is the case please restore the files from backup as you would in the event of corruption of any other file types.
Resolving The Problem
If you experience this issue the stream cannot be recovered, although the backup stream of the same name (but with suffix '.str-') should be intact. Please delete the corrupted original and use the previous backup stream.
If you have a specific stream that causes this when you attempt to reload it, and the save within Modeler appears to complete (ie. the UI returns for use from the busy hourglass cursor), then please, if possible, follow these steps:
1. Copy the backup stream in Windows explorer (the stream with the same name but with the ".str-" extension to , eg. "mybackup.str" - retain this stream as a master backup).
2. open the backup stream (with the same name as the original stream but a ".str-" extension)
3. document the exact steps that were taken to modify the backup stream so that it is in the exact state it was in immediately before the final save that created the stream file that you can no longer load without this error.
4. Confirm that it is repeatable (ie. confirm that if you again save the stream that you get the same error when you try to reload it into Modeler)
5. If it is, please provide the backup stream, "my backup.str" along with the documentation of the steps you made in step 3. so we can attempt to replicate the issue.
Related Information
Historical Number
30532
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Document Information
Modified date:
16 June 2018
UID
swg21503674