Do you have more information about the stack trace when the exception is thrown? From your description it sounds like a resource is not getting closed or disposed properly and is eventually running out of resources.
Edit: After seeing your stack trace it confirmed my suspicion that a resource was not being handled properly and it's running the system low on memory. As suggested in the comments you should contact the builder of the program and suggest that they debug it using a profiler and properly dispose of the objects, or to let them go out of scope so the garbage collector can dispose of them. Also you might suggest that if the error is occurring when a file is being loaded that they load the file via a stream using buffers rather than loading the whole file into memory at one time, and then release it after it is no longer needed.