Sorry for the delay - sometimes I miss threads that are buried in unrelated topics.
That log shows that you got an out of memory error while saving your project. How big is this project? Go to the “view” icon in the Gateway > Config > Projects > Manage and see how large it is.
After that it appears that the database stopped servicing queries, because your db connection pool was full continuously, although my confidence in that diagnosis isn’t very high. But thats what the logs are telling me, FWIW.
Can you give an overview of the stats of this machine/system. where are the pieces running, what are the server specs, how many clients connected, how many quries per second, etc.