[Solved] Lost database table and queries

[ESgt]

After working at a new club membership database for a week or so. Now when trying to open the table I get a dialogue box saying: The connection to the data source "<database name>" could not be established. The driver class '' could not be opened.
Could someone please show me how to recover this?

Using Agent Ransack to find all of my *.odb files I found a large number of backup files, apparently produced every few seconds.
They were in a directory ...\AppData\Roaming\OpenOffice\4\user\backup and with numbered filenames like fname.odb_978.odb
I took the highest numbered one and renamed that file to just fname.obd and hey-presto recovered my data table and queries.

[eremmel]

It might be that Java has been updated recently on your system. Go to Extra -> Options -> OpenOffice -> Java and select a Java version. Note that you have to use a 32-bit Java version.

[Villeroy]

When you select a version in the options dialog, you see the path of the selected version below the list. If the path starts with "C:\Program Files (x86)\" the Java version is compatible. Any path with "C:\Program Files\" indicates a 64-bit Java which is incompatible with OpenOffice unless your whole Windows system runs on 32 bit.
See Troubleshooting Open/LibreOffice and Java

[Villeroy]

Quick test on the file:
Change the file name extension to .zip instead of .odb. OpenOffice documents are zip archives actually.
If you can open the renamed archive with a zip tool it is rather unlikely that the file is damaged.

[ESgt]

It might be that Java has been updated recently on your system. Go to Extra -> Options -> OpenOffice -> Java and select a Java version. Note that you have to use a 32-bit Java version.

I cannot tell what you mean by 'Go to Extra ->...

[RoryOF]

Translation problem: try /Tools /Options/ OpenOffice /Java

[ESgt]

Translation problem: try /Tools /Options/ OpenOffice /Java

OK, found there: Location: C:\Program Files (x86)\Java\jre1.8.0_191 and see that there is a button for Class Path. With that I set the folder name. But there is no improvement after restating.

[ESgt]

Quick test on the file:
Change the file name extension to .zip instead of .odb. OpenOffice documents are zip archives actually.
If you can open the renamed archive with a zip tool it is rather unlikely that the file is damaged.

OK, made a .zip file copy and opened with WinRAR giving a list of 6 folders and 3 files:

[Villeroy]

Troubleshooting Open/LibreOffice and Java
Ignore the class path button. That setting is not relevant for your embedded database.
The zip content looks OK.