I deleted 500 MB partition. I thought it was a leftover swap. It wasn't.
I deleted it with Windows 10 Disk Management.
I could not boot pass the ZorinOS logo.
I tried to fix it by making the unallocated partition into 500MB Fat32 with Windows 10 again but it won't work.
I tried recovery mode in Grub with timeshift which included the grubloader recovery as well. It did not help me either.
You haven't deleted your EFI partition by any chance?
I think they are usually set about that size.
Are you able to post a screenshot of your partitions from Windows Disk Management or Gparted? That may help us understand what partitions you now have left.
Yes, you deleted your EFI partition. Since you created a new partition, you may try using os-prober to identify the Operating Systems on the machine and add them to grub or try Boot Repair...
It is undoubtedly the boot partition.
Being FAT32 file system, that is the only Linux partition Windows can access. See the partition mapping of my Zorin installation below:
Absolutely NOT. I know dual-boot is horrible when Windows 10 is on the same drive. That's why I put ZorinOS on its own SSD. It used to looks like @FrenchPress
's picture.