Cannot open file "...\Param.dat"

[bcummings719]

When I start the program, it says that it can't load the file Param.dat, Currency.dat, Countries_V6.CSV, SandiaManfacturers.CSV and CarbonBalance_Definitions.txt. I am using V6.26. If I try to do a project design I get a whole string of messages saying that it can't open the files for panels, inverters, etc. I fixed this once by reinstalling the program, but I do not have administrator rights on the computer and cannot do this again. How do I fix this?

[André Mermoud]

This is a problem which has appeared recently with some windows installations.

Please make sure that you have Windows reading access priviledges from your session, on the PVsyst installation files (normally c:\Program Files (x86)\PVsyst6.x.x\, namely the \DataRO\ subdirectory).

[Sylvain Pepoli]

Actually this error message and more generally file read errors at startup may happen when the situation meets the following criteria :

- You are running PVsyst from a non-administrator session

- UAC (User Access Control of Windows) has been completely disabled by the administrator OR only the VirtualStore has been disabled

You have two solutions

1. - Either add write permissions for simple users to the PVsyst install folder (quicker but less secure).

2. - Or you can enable UAC or VirtualStore back (slower but more secure) by doing one of the following actions as an administrator :

- enable UAC again in Control Panel -> User Accounts -> Change User Account Control settings,

- only enable VirtualStore in Local Security Policy -> Local Policies -> Security Options and enabling User Account Control: Virtualize file and registry write failures to per-user locations

Although, a fix will be included in PVsyst 6.3.5 (release date to be defined) which will allow you to keep your current configuration.