Help with double pendulum on a movable support

Questions
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1

I am new to Mathematica and I’ve made this double pendulum on a movable support which worked until now as there seems to be an error about pairs of numbers and scaled or offset form?? I cant figure it out. Please help. Edit:If it help i have found that it works with these outside but I don’t want anything outside at all

k = 3;
l = 3;
x2[t_] = x1[t] + l Sin[\[Theta][t]];
x3[t_] = x1[t] + l Sin[\[Theta][t]] + k Sin[\[Theta]1[t]];
y2[t_] = -l Cos[\[Theta][t]];
y3[t_] = -l Cos[\[Theta][t]] - k Cos[\[Theta]1[t]];
2

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