If a cell has a mutation that eliminated the surface carbohydrates, what problems might arise from this mutation?

Cell surface carbohydrates are required for cell-cell recognition process. The cell surface is coated with complex carbohydrates and are recognized by sugar specific receptors called as lectins. In absence of these carbohydrates, cell-cell recognition process will be hindered which will deter the signaling process.

Cell-cell recognition is also required for cell adhesion process. Many hormones, virus and bacteria attach themselves to cells using these surface carbohydrates. In their absence, the attachment would not be possible.

Cell-cell contact mediated by surface carbohydrates also play a role in controlling growth. For example: N-glycosylated protein is required for density dependent inhibition of fibroblasts growth. In their absence, cells would not stop proliferation even when they are overcrowding a space.

this is a good question! i'll do some research and come back when i have the answer!