Totally baffled on web site error ...

[bitsnpcs]

Hell RCPWISC,

does the Firefox browser in LL have cookies enabled ?
are there any ad blocking, or other addons added ?
do you have the restricted extras installed in LL
does the POS software require Java?

If not one of the above more information, not personally identifying or site identifying, may help one of the community to help you.
Eg;
which version of LL are you running that HP pc?
which version of Firefox on Linux and Windows?
what is the POS software brand, and its version ?