Currently Unavailable gun modification

               So, I don't know if anyone else out there is experiencing this issue as I am. I also wasn't sure which label to this under. Apparently, I am noticing that some of the gun's modifications are appearing "Currently Unavailable" and I can't find any information in the game or on the internet about how to get them to be available. I know these probably seem pointless to everyone else but what would like to know and so the developers see it too is how many other players out there are having the same issue? Here is the list of the guns and their modifications names that apparently "currently unavailable" right now for me. 

• The SOR 556 MK2 modification called the crawlspace, the M433 called the boiling point and cryosphere, 
• The B36A4 called the Veiled
• The KORD 6P67 called the Strapped In
• The USG-90 called the Autonomous
• The L110 called the Hazard
• The RPKM called the Warning Colors
• The M2010 ESR called the Lethal Force
• The M87A1 called the Icebreaker
• The P18 called the Gravity.

If anyone knows how to fix this then I would really appreciate it.