Steps to reproduce:

1. Create LLD
2. Change items nextid in ids table to 999000 (to easier reach expected result)
3. Generate 1000+ discovered items
4. Set 1000 rows per page in user profile
5. Go to Hosts-> Items
6. Select all

Result:
Appears alert "We are sorry, the maximum possible number of elements to remember has been reached."

Steps to reproduce:

1. first 3 steps as in previous scenario
2. Set 500 rows per page in user profile
3. Select all and press Mass update
4. Check "Master item" and press Select

Result:
always displayed loading in popup, because of error "Failed to load resource: the server responded with a status of 414 (Request-URI Too Long)"