We have been using a Base programme to run our community centre for the last 2 years with no problem at all. Yesterday we closed one Form and when we opened another all 4 Tables were missing. This means that we have lost everything. Is there anything that we can do to get them back? And How did this happen? Any help would be much appreciated. Regards Nick. 2 people on the system it is via Dropbox.
It may not be possible to help in this situation without actually being at the computer. There are many questions to be answered, each depending upon another.
You do not state if this is an embedded or split database. It may help to know the LibreOffice version you are using and which operating system.
An embedded database zips together all the pieces necessary for the database when it closes and unzips them when it opens it. This is a somewhat fragile method and has been known to potentially lose information. But your problem appears to be different in that the information was lost between forms opening and closing. Were the actual tables gone? Were the tables which disappeared used on the form which was just closed?
Dropbox is also a concern. They typically upload/download only those portions of the file which have changed and use compression for time saving. It may be they do the same for zipped files. Have you tried getting the file from Dropbox again?
Another possibility is a virus or malware (malicious code) was introduced somehow onto the computer and wiped out the information.
You can see at this point it is difficult to answer your question without answers which will probably lead to other questions. The best way possibly to get any solid answers in this situation is for someone with knowledge in LibreOffice Base and computers to actually examine the situation on the affected computer.