Restoring to the backup would be the simplest option. If you can't do this other options can be considered.  Do you have the error file for the unhamdled error message as it would be worth trying to see what caused the problem.

When this error came up before Matt Grose from Cumbria said he thought it could be due to data problems like Grid refs not being valid or not having a Spatial_ref_system – see http://forums.nbn.org.uk/viewtopic.php?pid=7494#p7494 . I think this is very likely given the other circumstances in which it has occurred and would therefore recommend checking your system for errors like these. Problems V2.zip which can be downloaded from http://forums.nbn.org.uk/uploads.php contains xml reports to check for the types of errors Mike Weideli and I know about and batch updates to correct quite a few of them – see http://forums.nbn.org.uk/viewtopic.php?pid=8931#p8931 . Hopefully the documentation in it will provide all the assistance you need.

How are you doing your export? Tools – Export Data will exclude unchecked observations and observations flagged as Failed/Pending Verification whereas Tools – Export Management will include them. For more details, see the on-line help: Help – Contents tab – Tasks – Exchanging data – Export NBN data. The note at the end of this topic was added to explain this in the latest round of Help updates. If the opening page of the help contains reference to versions 6.15 and 6.16 you have the latest version otherwise you will need to upgrade it – see http://forums.nbn.org.uk/viewtopic.php?pid=8812#p8812 .

I am hoping that if you clear any problems using Problems V2.zip you will be able to export your data on which custody has been transferred. Can you try this and then let us know if you still have problems?

If your data was exported to another system you could consider asking them to export it back to you although you would lose any changes you had done since exporting it to them. If it was last exported without reassigning custody it will be editable when it comes back. Which Site ID can edit records is controlled by the Custodian field in most of the tables in the database. This is changed to the specified Site ID when custody is reassigned. In Recorder 6, Show Metadata (icon that is an aquamarine circle with i in it) will tell you which Site ID is the custodian of the selected item if it isn’t the Site ID of the system you are using.

Until problems like the ones you have experienced are corrected, users are strongly advised to backup their database before reassigning custody so that they can restore the backup if the export fails or they find they are no longer able to edit data.