Thankyou, Felipe, for your comments concerning multiple versions of Lazarus. I am now using only one (different) version on each computer.

This refers to your comments concerning the installation of component packages into Lazarus/FPC.

They have been running OK once installed in Lazarus 0.9.26/FPC 2.2.2. However, on trying to install them into either 0.9.26/2,2,2 or 0.9.28.2/2.2.4 or 0.9.29/2.4.1 which have been installed individually on three different computers without any previous history of Lazarus (2 are running XP, 1 is running Windows 7) I always get the same errors - "Can't find unit Unix", or "Can't find unit Controls", etc. etc. Another message is "Argument can't be assigned to", despite being perfectly happy to be assigned to in a previous installation. I have one other computer which already still has the component installed and when running "Build All" the application it builds OK using the previously installed component (running with 0.9.26/2.2.2). I haven't tried installing other components on this same computer for fear of affecting its performance with the main AlSortGrid component.

They are all source code, and it is when I try to compile / install them that the problems occur. I have checked the source directory and it is OK, and it is the same on all computers (except for the FPC version directory), including the one with it still
installed OK. I have also checked a backup copy taken several months ago, and this also points to the same directories.

It is very mysterious as to why it rejects all attempts to compile on all computers and which have or have not seen Lazarus before, but why standard Lazarus components (eg StringGrid, on which AlSortGrid is based) run OK. I do not want to change the first
computer configuration which is OK otherwise I may not be able to reinstate it, but I will be happy to try anything on any of the others (apart from a System Restore which would affect other settings on the computers).

Regards

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Hello,

Which component package is that? Where did you get it from?

Technical wrote

on three different computers without any previous history of Lazarus (2 are running XP, 1 is running Windows 7) I always get the same errors - "Can't find unit Unix"

Well, it will never find unit UNIX in Windows =) Looks like a problem in the source code

, or "Can't find unit Controls", etc. etc.

This one shouldn't appear.

Another message is "Argument can't be assigned to", despite being perfectly happy to be assigned to in a previous installation.

There were some changes of changes between FPC 2.2 and FPC 2.4 which require code change.

It's hard to say much without knowing which components we are talking about, but to me it looks like the package needs an update to work with newer FPC version.

Technical wrote

Another message is "Argument can't be assigned to", despite being perfectly happy to be assigned to in a previous installation.

See http://wiki.freepascal.org/User_Changes_2.4.0#Treating_direct-mapped_properties_as_regular_fields

Jonas