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You can do the lubrication yourself. And it might help! if the adjustment is also needed, and is too tight.
Here's how to do the adjustment:
The solution that you should try first, is that the belt might need readjusting and lubrication (with the special, non-grease, lubricant these treadmill belts generally require.)
The belt should be adjusted, generally speaking, so that it is loose enough that it does not quite slip, but nearly that loose.
If the belt is adjusted (or, has shrunk up with age, and lack of lubricant...) too tightly, then it can stop the treadmill from working or running. An over-tight treadmill belt can cause wear, or even damage, in many other ways, such as by overheating the motor.
If you need direction to a source for, or a guide to, lubrication of a treadmill belt, let me know.