This message sometimes happens when current save could not be completed.
In most cases you retrive an error in the log files.

In your case, you possibly faced a Timeout or somethong like that, so maybe the answer was directly retrieved from Apache (or any other front end).
Maybe you could have a look at your apache logs.

One hint : you could add $debugQuery=true; in your parameters.php file.
This way you'll have a trace of every query to the database. This could give an hint of where issue happens.
For instance, if several tries end on different queries, then a Timeout is a good suspect.

You are quite right, I also figured it had to be a server-side error, since I had nothing in the Projeqtor logs.
And indeed I got this:

PHP Fatal error: Maximum execution time of 300 seconds exceeded in C:Program Files (x86)ZendApache2htdocsiPMPmodelpersistenceSql.php

I notice also you have made an optimisation in V4.1.2 (I'm still on V4.0.6):
"Move project (change WBS) optimization for projects with many sub-projects and/or activities"
=> do you think this could help to prevent such an error ? (I guess also increasing the max execution time would be ok, but it seems like a "band-aid" solution 😛 )

Anyway, thanks for your quick input !

Yes V4.1.2 should fix your issue. 😛

First there is an important performance improvement so that operation will take must less time. :woohoo:

And also the time limit is dynamically increased to 5mn 😉
(will not work if PHP configuration forbids dynamic changes) 🙁