Gateway crashing regularly

Hi,

Since a few days, users regularly complain of their reports showing no data. After checking, everytime it is caused by the data gateway not returning anything more.

From the gateway logs we see the error DataAccessException/Wrapped(InvalidOperationException)[HResult=-2146233079] happening.

Then all requests to the gateway shows MashupException encountered while accessing the target data source.

If I restart the gateway, everything works fine for a few hours, then it breaks again.

We have been using the current set-up for more than 2 years without issues. Any ideas?