I have two customers using pre 2018 8.4 versions that I wish to upgrade to current.
Both these when I try and upgrade fail with the following error:

2018-02-09 19:15:12 (-1) global boolean
2018-02-09 19:15:12 (-1) dump of call stack
2018-02-09 19:15:12 (-1) call stack entry: alocalizations/Tools/WindowTagTools.hal: SETPRODUCTTAGS
2018-02-09 19:15:12 (-1) call stack entry: english/Haengm.hal: (no function )

I cannot trace this error in my code.
Can anyone advise the reason please?