Unfortunately this error message doesn't contain a precise information. Please close GeODin and open it again, because it is possible that the error persists when you just close the message. Then the message will reappear with following actions, which doesn't have to do anything with the error or the cause of it.
If the you get the error frequently please let us know, at which action the error occured, what you did before and/or which methods are opened in the background. Did you do some data editing without saving and then a switch to an other method?
This information would help us to solve the problem as soon as possible.
Thank you very much for your cooperation.