I verified this with Procurve switch which does support spaces.
IMC at latest patch would not allow creation or edit of VLAN names using a space on this type of switch, even though the help tip indicates spaces are supported if the device vendor allows. Do not see any settings, so must be a bug in the vendor spec part of the code.
IMC will synchronize the vlans from the switch and allow edits that replace the space with another valid character such as _
I don't use spaces in names as most devices use a space to separate parameters in CLI commands.
Maybe just replace the spaces? Easy enough to do globally in imc.
But if that's not possible you will need to flag this to HP.