This question is quite broad, I don’t know what you want to ask about.
I will briefly talk about the types I know, which are basically about patent rights:
(1) The issue of patent ownership. It is possible that a certain patent does not belong to an individual. It belongs to the company, such as a service invention; there may also be patent ownership issues between cooperative units, etc.
(2) Issues with the scope of patent protection. There may be problems with the scope of patent protection and the product cannot be well protected.
(3) Patent right stability issues, such as insufficient novelty, drafting issues, etc.
(4) Once you have a patent, it does not mean that you will not infringe on other people’s patent rights. Patent rights are only exclusive rights.
That’s all I can think of now. If you have any other questions, you can ask.