Thank you !
That helped me a lot.
After upgrading to 3.51 the gallery is written :
” [gallery ids="2711,2712,2713,2714,2715,2716,2717,2718,2719,2720,2721,2722,2723,2724,2725,2726,2727,2728,2729,2730,2731,2732,2733"] “
Before 3.51 it was written:
” [gallery include="2750,2749,2748,2747,2743,2742,2741,2740"] “
A solution is – changing the “include” word in the plug-in . Or wait for the update.