Oh okay, it IS due to permission on the folder, thank you so much Kronbits ! I was running as Admin, but I still needed to give the folder special authorization.
One quick way to do it is by placing the folder on my Desktop, but if I want to keep it in the ProgramFiles folder, here is how I changed the settings and permission, if anyone has a similar problem in Windows 10:
1 ) Right click the folder: Choose 'Give access to', then 'Advanced Sharing...'
2) In the Sharing Tab, click on 'Advanced Sharing'.
3) In the dialog that opens, click on 'Permissions'
4) In the list on the bottom, select 'Allow' for all the three options (Full Control, Change, Read)
5) Click Apply and OK to return to the previous dialogue. Click Ok on the previous dialogue, to return to the first dialogue.
6) Open the Security tab on the top.
7) Click on 'Advanced'
8) Now for a user who doesn't have 'Full Control' as their Access parameter, you select them, if necessary select 'Disable Inheritance', so you can edit their parameters, and then click edit.
9) In the dialogue that opens you check 'Full Control' and normally all other boxes should be checked too. You can click on 'Show advanced Permissions' to make sure all permissions are checked and enabled.
10) Click OK to confirm.
11) Do that for every user that uses Vecmaker.
12) Click OK. In case the Apply button is highlighted, click 'Apply'. Then click 'Close'