Multi Size Mosaic

I am trying to mosaic multiple sences but for more then 4 sences it process to visiualize but whe I want to save it goes to hang after saving up to certain percent…

Can you tell a bit more about the mosaic you are doing?
Which input data are you using OLCI or SLSTR, Level1 or Level2?
Which spatial resolution does your mosaic have and in which area is it located?
Also, your computer can be a limiting factor. How much RAM does it have? It should have at least 16GB, with less you can experience such problems you describe.

I am using S2A MSI data Level-1
The data is in its original resolution i.e 10, 20 meter for Visible and SWIR bands
I am doing Multe Size Mosiacing
My computer has 16 GB RAM and Xeon Processor

I am also facing another problem i.e. I have processing data and making some raster bands using band maths. I did it for 20 (twenty) set of bands. All twenty math bands coverted into band through covert band option but after twent SNAP is not able to do for the next set i.e 21th one.

I am also having the same problem with mosaicing two : S2_MSI_Level-1C images. The resulting output bands are null value raster files. Like Najamsyed; I am working on a 3.3 ghz xeon processor and 16 gb desktop and I have followed the SNAP - multisize mosaicing tutorial on the EO open science youtube channel. Is there any solution ?