1) download the libiomp5ui.dll found here:
(Ich weiß nicht ob ich den Link hier rein stellen darf

)
2) Extract the dll file into a new folder
3) Verify the name of the folder from the error window. It is very important to read the error to know the number of the folder to create for Vegas.
4) Rename it, for example on an Italian OS the folder is 1040, on a German OS it is 1031, on a Polish OS it is 1045, and so on.
5) Then put the folder in one of the following locations:
64-bit Vegas
a) C:\Program Files\Sony\Vegas Pro 10
32-bit Vegas
c) C:\Program Files (x86)\Sony\Vegas Pro 10
Example: C:\Program Files\Sony\Vegas Pro 10\1029\libiomp5ui.dll